How fussy are you about the external condition? I do have a System 80 here that I'm mulling over putting on the market. It's a 16k model black label, but with the arrow keys and lower case. Goes well, but it's a little beat up externally.
I'm quite relucant to sell it because it could be a good parts machine for my two showcase System 80s. However, I'm wanting to get a TRS80 Model III or IV and I'll probably have to import one. That costs big money, so I need to raise some cash.
As I said it's a little scruffy. All the keys are there and they all work. However it is a little yellowed, and a few mm of the plastic around the edges of the top half is missing in areas. It doesn't have the TV RF modulator cord, or the holder you wrap this around. A few of the screwholds holding the case together are stripped, but there are enough that work to keep the case together.
I'm thinking the value to me personally (as a parts machine) is probably more than the market would pay for the machine, but I might put it on Trade Me at $150 or so and see what happens. Given it's external condition, that price is probably on the highish side, but working ones are rare beasts these days. If no one bids, then I'll just keep it.