I went to a local Game Store for the first time in well 10 years.... I was a little disappointed to see that they didn't sell a single dreamcast anything... but thats ok.. PS2 / Gamecube / X-box only...
but I noticed something. They have some really really expensive plastic arcade controls for sale.
I bet if someone asked a manager, they might sell on consignment peoples arcade machines or control panels. Especially if you hacked both xbox and ps2 controllers and could sell them either way.
Anyway, they seem like the place that if they could mark something up 100 bucks they might like selling the cream of the crop.
I don't know if anyone has ever approached any store managers to see if they would even consider it.