I seen a few of these yesterday for 4.98 at Walmart (YMMV).
edit: Here are a few brickseek links, anyone have skus for the adventure flashback blast and star flashback blast?
Activision Flashback Blast!, Pitfall
Atari Flashback Blast! Vol. 2
Atari Flashback Blast! Vol. 3, Pong
Bandai Namco...