GoG is selling limited quantities of games at very low prices - they have 101 they're planning to go through:
They just finished with Dark Eye: the Chains of Satinav for $4.00
Then they went through 100 copies of Shelter for $4.00 in under two minutes
Currently it's Deus Ex: Game of the Year Edition for $2, 400 copies. I'm not going to try to keep up with the deals; head over there and watch for yourself.