It’s the ammo that would make your upper a desirable thing for someone to purchase, particularly if the ammo you have happens to be the old Russian surplus 7n6 variety that came in spam cans of 1,080 rounds and two spam cans to a wooden crate. It’s been a while since I checked, but at last glance, a spam can of that stuff was selling for between $500, and $600 per spam can.
The main reason why the upper receiver you have became popular for a short time is that around the time when it was produced, there was a ton of the Russian 7n6 ammo being brought into the USA and it was being sold extremely cheap. I believe the first crate of it that I ordered came from AIM Surplus and was priced under $300 at the time. That’s for 2,160 rounds of rifle ammo! As such, a lot of AK shooters bought rifles in 5.45x39mm to take advantage of the cheap ammo, and that left the door wide open for Smith & Wesson to jump in with a decent AR15 upper for all of the AR shooters to save on ammo as well.
Unfortunately, the land of the free turned out to be just some words in a song, as the good ole government decided that they couldn’t have people arming up with a bunch of cheap Russian surplus, and they arbitrarily banned importation of the 7n6 surplus without a whimper from the so called gun rights groups. Almost overnight, people began abandoning the 5.45x39mm cartridge altogether (myself included), and the once popular AR uppers chambered for it became next to worthless.
Now, with ammo prices being what they are, a good stash of 5.45 ammunition would be the motivation needed for a guy to invest in one of those uppers. I don’t know how many thousands of rounds you have for yours but I would say currently that they’re worth around a grand per crate (two tins), and if you had at least a couple of crates worth it would be enough to entice someone to buy into the caliber. My best estimate for a price that would be fair to you, yet move the package rather quickly would be around $400.00 per tin of 7n6 plus $500.00 for your upper and magazines. I would advertise it on AK specific forums as well as gunbroker to maximize your audience.