Maybe it is way more simple: Want to pay $35,- for a great game which will bring you hours and hours of building fun? YES → Buy the Game. NO → Don't buy the Game. I've bought two keys of this game. 1000+ hours of game time, and still love the game. No other game, for me, has this low price—playtime ...

@Devs: bought the game again.
It is the only game I play year after year, it seems that I will never get bored.
It is my way to support you and show my appreciation for this great game.

And if we calculate price per played minute ... this is a really cheap game, even when I own two key's