This entire trilogy is a download. What I think you might be thinking of Trine 4 physical edition. Hope this helps (y)
isnt this the one where only the first game is included but the rest are digital downloads?
I'm seeing around £13.85 in Russian store, according to online site
The port quality it fantastic. Played all 3 games on it and didn't have any issues whatsoever
£22 at Amazon and Sainsbury's if you want it physical . Whilst this is a good price for the e copy.