Hotel would be Sokos Hotel President which is great location for party people.
Rooms would be around 65€ and the suite with sauna would be around 200€. I didnt get the info how many people there can sleep.
Only problem is that the hotel manager that my friend knows is on holiday till next week, but I should still get the confirmation about the prices. And those fixed prices they cant give if they have reservations to book hotel full obviously.
So now we have some info to plan thing ahead and what is the best option