1. Helsinki is just plain not cheap. You might find something cheaper in Vantaa, which is where the airport is. Most lodging in Vantaa has free transportation to the airport where you can catch an express bus (around 6 euros) or a regular bus (cheaper) to town. The ride is maybe 40 minutes with frequent service.

We stayed at Hotel Arthur, which is next to the YMCA (maybe owned and run by the Y??) which was an excellent location and a good value (by Scandinavian standards). There might be hostel lodging at the Y.

I’ve seen good reviews about the hostel on Suomenlinna island, but I think it would be terribly dull as Suomenlinna is a basically a museum with a little residential housing and a couple of tourist shops around. I don’t think anything on the island would be open after dark, especially in winter…. Everything on the island seemed to only be open between about 10:00 AM and 4:00PM when we were there in August.

Have you thought about staying in Tallinn and taking the ferry to Helsinki?

how about the Summer Hostel Satakuntatalo I heard it’s good.

Thanks for your help.
We luckily got return flights for £40 and I think we are going to stop in the Olympic Stadium.
Thanks again