> really doesn’t know how to test old electronics? Yes. There are so many things out there that no one person could possibly know all of the ins and outs of a device. There are a number of vendors there that know what they're selling, but there are also many who are dealers or estate people and have absolutely no idea what they have or how to make it work, and some of it's simply too old to even use anymore. You also have to look at things of this age - electronics doesn't age well, you get devices that are 50-60 years old and parts are breaking down. You could potentially plug something like this in and destroy it because all of the capacitors are shorted. The type of device is also a factor - who knows analog computing these days? Last, just because it had an eBay price doesn't mean anything. One sold, did the buyer pay for it? Did they complain? Was the description of the item accurate? Who knows? The hassle of dealing with online sales may be more than this guy wants to mess with. Maybe he's just using it as a conversation piece to bring in people to his booth. Maybe this guy tried to sell it online for that price and couldn't - there's a very limited market for a piece like this. I like computing history, but there's 0% chance of me ever wanting this thing, it's big, useless, and useless other than a display piece. It's all about knowing your market, and there's probably less than 1000 people in this world that would want something like that. Literally nothing at this place is sold working. It's all as-is, most of it's untested.