It's worth it for Osmos alone. That game is amazing. You could pay $10 for Osmos, get 4 games for free, and give all the money to charity, and be very very happy with that purchase.
If you're on the fence about Machinarium, you can play the first 3 screens in your browser for free right here: http://machinarium.net/demo/
Anybody who doesn't buy this right now should take a long hard look in the mirror and ask themselves, "Do I actually like games? Or am I sham?"