Last gun I sold was a Walther P22, 1st gen. Decent gun, but the trigger was meh, and so was reliability. Got 280 for it and used that to buy an advantage arms slide for my Glock. More reliable and replicates my carry pistol almost exactly. Picked up a frame too and now I have a dedicated Glock .22.
Before that I sold a Norinco sks. Put the money toward an AR upper and goodies.
Also sold a Ruger SR45, which was a nice shooter but a little unreliable and very heavy.
Only 3 I’ve ever sold. I’d only take the sks back. It was heavy and awkward to load but since it’s hard to get semi rifles in MA currently it’s a nice option.