Not really a gouging story, but more of the opposite. 
So I put my Turbob collection up on a local gaming FB group. Not for sale, just to show off a little. 
Now, it is nothing remarkable. A PCE Duo with region switch from Keith Courage, a multi tap, 5 controllers, and 13 games. 
I had someone ask me if I'd be willing to sell. I told him to make me an offer. So he says he did some "research" online and found bundles like mine on Ebay for $200-$250...
I told him if he is finding things like that on eBay, to go ahead and buy those instead.