I've had them listed on FB Marketplace for months. In that time, I've sold four (3 to one guy, one to myself), and still have 20-ish more.
i5-13500E, 32GB DDR5, 512 GB NVMe, scratched and dinged a bit for $500 is practically a steal! Hardly anyone's biting or clicking, I don't get it...
New open box models (not scratched and dinged), if anyone's interested: https://www.ebay.com/itm/188355326179
Edit: they're intended to be retail POS PCs, like cash registers. (The motherboard literally has a header for a cash drawer!) So unless you're a particular kind of retailer, you're not asking your distributor for them. If distributors aren't looking for them, our B2B buyers aren't buying them. If they were Elite/Prodesks, Optiplexes, or Thinkcenters, they'd probably be gone by now.
Why don’t you part them out? The market for the parts will be more liquid. You might sell faster and at a higher price. You could try doing it once and see how it goes.