interrail

Hi

I’m travelling around Italy with a couple of friends and was wondering whether it would be worth my money to buy the ‘travel 3 days within 1 month’ interrail ticket. We’re travelling between Rome, Florence, somewhere on the coast and finally Venice. I arrive in Rome and so will have to make three longer train journeys between cities, which, from what i’ve found out, seem to cost around £45 each. The ticket is £59.

I would like to know if someone has used an Interrail or Eurail pass. Im planning to travel across Europe during a month going trough Barcelona, Turin, Milan, Budapest, Belgrade, Kotor, Dubrovnik, Split, Hvar, Prague, Amsterdam and then returning to Barcelona.
I can buy a Interrail pass but i read in the web page that you cant use it in the country were you reside. I live in Uruguay, South America but i also got Italian citizenship does this mean that i cant use it in Italy?.
In the forums in here i have read that is not convenient to buy a train pass.
What do you think?
Help please.