I paid less than $5. It was that or not have the game.

I'd be more than happy to say thank you in person to one of the devs.

2DBoy offer[ed] World of Goo to the world for whatever price people want[ed] to pay for it so I didn't pay what I thought it was worth.

The game kept me occupied for one evening, quite a long evening, it was fun. I did skip one level though.