On Reverb a bunch of BK-7m's sold in November-December 2019 for about $700 give or take $100 bucks. I think they were $999 new so I don't understand why Roland took them out of production. Obviously there's still a demand for a compact module with Chord Intelligence.

I don't know what kind of enforcement mechanism Reverb has for deadbeat bidders, dishonest sellers, etc. eBay is the largest online nexus for pre-owned goods. It provides a valuable service, so the threat of a lifetime ban is usually enough to make folks work out their differences. Also, the requirement to pay on PayPal before an item is shipped keeps buyer and seller at arms' length. Maybe I watch too many crime dramas. But with Craigslist, I fear being held up at gunpoint in a parking lot somewhere, losing the money AND the goods. YMMV.