the database says Sean Kelly's Multicart is still available through him. It is not available anymore it is confirmed through him and this should be changed as well as rarity too. Since you can't get it through him anymore would make this insanely rare to find even on Ebay so it should be adjusted.
There is some other listings that are off, at least in my eyes
The Fire Command seems to become insanely rare to find even on ebay I haven't seen one on there in over two years and it would probably go for an insanely high price now, also the competition pro would only be worth around $30 now and the Master play interface is probably only worth around $50. And the Starcon and Triga Elite should be listed as R10s
Game wise, Pitfall and Astrochase seem to turn up less than the guide says they do and K-Razy Shootout turns up so rarely now even on ebay and is constantly sold for more that $50.
Stuff to add
Controller Y splitter and the Console Dust Cover.
Joe can you confirm any of this stuff, or forward this to the proper section editor/s