I'm selling a few gems from the collection on ebay this week.

For the Atari 5200,
Complete in the box Bounty Bob Strikes Back!
Boxed Wico & Comp Pro controllers
Boxed Masterplay Interface (rarer box design)
Newport controller guides (very rare)
Starcon controller (very rare)

as well as some CIB 2600 & 7800 games (all uncommon & semi rare)