Expander Model 1

[Brad H]

Curious about this machine.  I've seen a few come up on ebay and they've sold for not much money, mistaken as mere Apple II clones.  I read Lee Felsenstein's account of creating them and they seem like interesting machines.  Wondering what sort of value is reasonable to pay for one and how hard it would be to find or rig up a power supply, since they are usually missing that in auctions.