Didn't know how to message this 2 u while u were offline but gamersgate has Mafia 2 on special for $10.18 for the next 3 days at http://www.gamersgate.com/DD-MAFIA2/mafia-ii
It says 3rd party DRM under system requirements but not sure if this is for steam. They've got an agreement with steam for some of their games catalogue( I've bought a few other games with them then redeemed it through steam).

Civ 5 is going for $7.49 at http://www.gamersgate.com/DD-CIV5/sid-meiers-civilization-v for the next 3 days as well.