The community around buying and selling gear and just watching awesome stuff pop up for sale regularly is one of the reasons I’ve stuck with the site for so long.
Other than FredMiranda, e$ay, Craigslist, I’m not sure what other options there are (I’m not on FB).
Is there any chance something like photomarket could pop up in the fediverse? What other sites are you trading on?
They also buy, but I haven’t used them. The couple things I don’t still use have been passed on to friends or family.