[Xeronations]

http://thepiratebay.se is great for cheap games.

He requested Steam keys only .

Also, GamersaGate can be a good place to get Steam keys, although only some of the games they sell are activatable on Steam.

And it could be risky because Steam doesn't allow purchasing keys then activating it on Steam.

GamersGate is a legal reseller, so you shouldn't run into any problems with them.