Probably not the absolute cheapest prices these have ever been on sale for (from places like Steam etc) but a good deal for DRM free copies which are all up to date and work on modern computers. A good standout here is a completely DRM stripped copy of Far Cry 2 Fortunes Edition for $4.99!
Blood (One Unit Whole Blood) - $2.99
Blood 2: The Chosen + Expansion - $2.99
Duke Nukem 3D: Atomic Edition - $2.99
Far Cry - $4.99
Far Cry 2: Fortune's Edition - $4.99
POSTAL: Classic and Uncut - $2.99
POSTAL 2 Complete - $4.99
Unreal Gold - $4.99
Unreal 2: The Awakening SE - $4.99
Unreal Tournament GOTY - $4.99
Unreal Tournament 2004 ECE - $4.99
XIII - $2.99