Not much to report on the eBay front. Some interesting Casio synths, however most of them have nothing that you can listen to. No samples or video clips. Just a snazzy paintjob and rant like description.
The Realistic Reverb Unit on the otherhand is a different story. I previously thought of bending those, but looks like WATERSHED has done that already. This seems to be a resell however. The point being is that these units are cheap ( $10-$15) and would be great Modified effect units if done right with Oscillators and some bending.

Other Realistic/Radio Shack items to consider.
RadioShack Effects generator
Video Mixers
Please excuse my non-ad-farm links. I applied for a Comission Junktion account twice, but they don’t want to give me one seems like. 🙁