Yup, the piano marathon is free of charge!
I'm gonna be there, I hope to see you there. I booked a hotel close to the concert hall, but I am not THAT fanatic that I will be able to sit there and listen for 10 uninterrupted hours ... I suppose nobody is, so the audicence will most likely be "circulating" the whole day/evening.
The concert hall is fairly big, yes. It is, in fact, this one:
(I don't expect you to watch the whole clip, ha ha.)
This will be minus the royalties and the blue N carpet etcetera. I have never been there in person myself, though, so I'm looking forward to it.
The tickets to the "Final Battle" concert on Sunday were really not expensive either, just 190 SEK. That is the elite of Swedish pianists so I expect a lot from that one.