Does your tour group allow people to buy their own airfares if they get a better deal? Do all 18 have to travel on the same planes?
 
The reason, I think, that the 18 fares are higher than the fares you found online is that there are only a few tickets in each of the cheaper booking classes. So when you need 18 tickets, you are bumped up to a higher booking class.
 
I once worked for a company that was able to get a great deal for dozens of us to fly at a cheap rate to a particular destination, because it did so much business with Air Canada. Is there any chance anyone from your university can negotiate such a deal?

Does the agent specialize in group bookings? Basically, as Traveller pointed out, airlines usually have some limited number of seats available at the cheapest current price, and it is nearly impossible to buy tickets online for 18 people. (That is if 7 seats are available at $950, 9 more at say $1100, and the next 9 at $1400, quoted price for 18 people will be $1400 per person.)

IMHO the flexibility you mention is worth paying a small premium, but not as much as 50% more. My suggestions would be to contact
STA travel (nationwide student travel agency);
two or three large agencies that may specialize in group travel (perhaps even Orbitz or Travelocity);
airlines directly (you’d probably have better luck dealing with European airlines then with American ones: they have fewer people working on the US side, hence less red tape).
In all of those cases make it clear to whoever answers the phone that you need to talk to a group booking specialist, since ordinary sales agents may not even know if their agency/airline offers special group fares.

Thanks for the replies. I have contacted a couple of airlines about group bookings and also Student Universe. No replies yet. I don’t think the travel agent specializes in group bookings. She just does all the travel associated with our school and other state employees.
We’re not using a tour group, but organizing the trip ourselves (Me and a co-instructor). We used EF Tours last time we did it and didn’t like it for pedagogical reasons.
We considered having students buy their own tickets but there are two problems. One, it could turn into a logistical nightmare. Two, most of our students are first time travellers and wouldn’t be comfortable arranging it on their own.
My co-instructor has been in contact with STA but their price was also around $1400.

Given your comments, perhaps it would be smart to separate the group into two separate sub groups and buy tickets on-line that way, avoiding the higher group booking prices.
One of the advantages of group tickets is the flexibiilty in putting names on tickets but perhaps if we waited until the end of February to purchase tickets we could have a commitment from each individual at that time and be willing to put name to ticket.

Any guesses as to what a kinds of fares might be available from Denver to Edinburgh/Glasgow/Manchester/Newcastle in February? We made our budget with the assumption we could get $1000 tickets.

You might want to make travel insurance a prerequisite of this tour. Then if a student had to bail out for an insured reason, he/she could get most of their funds back.
 
I would also check to see what sort of liability you are assuming here, by organizing this tour. I hate to sound so overly legalistic, but it is a realistic concern.

Traveler’s comments notwithstanding.

It may indeed help to split your group into two. But you should not ask everyone to make separate arrangements because that will certainly lead to logistical nightmare. Out of 18 people potentially flying  18 different inteneraries at least a couple are bound to have some sort of misconnection and will hold back the whole group.

Did you try to talk to British Midland? They have direct service from Chicago to Manchester and historically they had decent fares on that route. They have some sort of a feeder agreement with United that has something like 10 flights daily between Denver and Chicago. So even if there are not enough seats in the cheapest booking class on one flight, splitting your group only for that portion of the trip could do the trick.

I could see a problem in what you describe with people on 18 different itineraries, but I’m pretty sure I’ve also seen many advertised tours where the participant is given a meeting point (like a hotel in Paris, for example) and told to arrive there by a certain time (Rick Steves tours are done like this, I think). So it’s all a matter of how much responsibility the participant would have. Maybe these are college students with little experience and this wouldn’t be appropriate.

However, as I mentioned, this all is pinging my liability buttons, because I’m sure licensed tour operators are fully insured. (Sorry, I know I’m repeating myself, but even over the Internet this makes me nervous.)

I agree that (potential) liability issue is not to be taken lightly. But it is not obvious to me that asking the students to buy their own tickets makes OP less responsible for anything that might happen during the trip. At least as long as each of the students is accompanied by either OP or their colleague, they keep the situation under control.

Besides, I presume that whenever Rick Steves clients get stuck in connecting airports because of labor or weather issues, the rest of the group just leaves without them. You can’t (nor should) do that with a student group.

I totally agree with you that the liability issue would still be there. Hopefully there’s an easy solution.

How old are the students? High School or University?
 
I have been operating tours for the past 20 years.  I do not carry any liability insurance anymore due to the high cost. One, have students (parents, if student under 18) sign a terms and conditions contract that states you are not liable for any circumstances that occur from the travel providers, airplanes, city transportation, hotels, optional tours, or improper and/or illegal behavior of the participant,etc.  You can copy the terms and conditions from other travel companies, EF, Conticki, Rick Steves, etc. and add your name changes.  Be sure you state that you and the other teacher are only tour escorts to assist in the arrangement of transportation, lodging, tours, etc.  You do not provide supervision, medical or parental control. State that clients are legal adults and are expected to act like one or suffer the rules/laws of the local city and country you will visit without the help of the escorts.  The students are legal adults and it is time they grow up and take responsibility for their actions. You may also want to place in print that this tour is not sponsored by the University(name) or the university system(Name).   Even if you have this contract signed, you are subject to law suits, but you are free and clear as long as you are not negligent on your trip. Meaning that your actions or lack thereof did not cause the accident or injury.
 
As for the airfare, I have found better deals on the internet than what any group department can offer.  I just booked or had parents/students book a flight through Travelocity on BMI that is operated on United Airlines from LAX to London in July for $1,007.00 all taxes and fees included.  In November the fare was $940.00 The same United flight runs $1,200 – $1,400 on other web sites even on BMI and United.
 
Over the years, people want more flexibility. 3 types of clients.
People want and should learn how to search and book on the internet. 
This way they get the credit card miles and some credit cards offer insurance protection.
Parents want to use their credit card miles before they expire.
People want you to do all the work and they will write a check. (If you do the last one, have them sign a contract and pay you in full before you book the air flight) You are covered and you earn free credit card miles.
 
My suggestion;
Plan everything out on paper.
Read over tours and terms at ricksteves.com and other companies.
List itinerary, activities, what is included, what is NOT included.
I do not include meals for more flexibility and let the students decide on the food they eat and they interact with the restaurant staff and local markets.
List 2 flight options from Denver that get in within one hour or so of each other.
List date you checked internet and print
“as of this date../../… the price was $000.00 and is subject to change. NON-REFUNDABLE / NO NAME CHANGES ALLOWED
Type up flight schedule and advertise Option # 1 and Option # 2 when # 1 price increases.
BOOK NOW and SAVE $400.00 SEATS ARE VERY LIMITED!
I would also have the students sign up for your land package and charge a NON-REFUNDABLE FEE from $75.00 – $200.00 NO name changes allowed.  This will scare away those that will flake out later and you will only get serious applicants.
You can tell them that if you don’t loose money on their cancellation, they won’t loose it either. Very fair in today’s world. But be careful, due to their cancellation, you may loose the cost of a bed in a double room if one person cancels.  Suggest Trip Interuption, Medical and Cancellation Insurance through www.accessamerica.com or www.travelguard.com NOTE: They will not be covered if they just want to flake out or if they are scared due to terrorist threats.
 
GOOD LUCK.  I have enjoyed every trip for the past 20 years.
 

Thanks for all the info. Got a quote of $1056 from Student universe for a group booking. Still working on getting commitments from participants. They are college students.

Have you seen this one yet? http://farecompare.h…

Seems like you have got the flight down. I was going to let you know that I am a college student currently studying at the University of Edinburgh. If you wanted any advice of things to do in Edinburgh or Scotland/the UK in general. Feel free to message me!

Cheers!

Ben