Why it costs money?
Because Badspot pours his blood, sweat and tears in it. He isn't making this game because he's bored, man. He's making it so he can pay off whores, debts and groceries.
The first version was free because he was letting people get a taste of it. Now that's aside, we got a less buggy, more stable and enjoyable version of the game.
Enjoy it. Pay for it. Be happy.