MacPlay lists some Mac games for $5 (plus shipping).
Titles include: Aliens versus Predator Gold Edition, Big Money Deluxe, Birdie Shoot, Earth 2140, Fallout, Fallout 2, Feeble Files, Giants: Citizen Kabuto, Heretic II, HeXen II, Icewinddale, Incoming, JinniZeala Pinball, Knights & Merchants, Mummy Maze Deluxe, Sacrifice, Snowball Run, Sin Gold, Zork: Grand Inquisitor
Until August 31st. Shipping is $8 in the US.
Link: MacPlay Specials