I bought a super nice Blackout from a Pinsider in town for Expo---I'm really enjoying it.
My buddy grabbed a reworked board from the gentleman who was mostly selling reworked boards. Excellent handiwork and a fair price for several hours of tedious work we didn't want to do. Fixed the problem with his game, to boot!
It is not clear to me why anyone, from a business perspective, would get a booth at Expo to sell sundry used pinball parts (unless they happen to be super local), but it makes the show more interesting and I appreciate the effort!