When I lived in the city, before lockdowns and brick 'n mortar fails, I used to go to a few select dealers and trade. We had a symbiotic relationship. Because of that, and the times, I always had interesting gear coming and going.
Selling? In pre-Web days I'd run newspaper classified ads--, you'd get three or four lines for a few dollars, lasting a few days. Friday, Saturday and Sunday--the weekend special. Those always brought in calls, for either cash or trade. Sometimes they brought in more. Once I had the police show up to check serial numbers. I didn't mind it, because one of the cops bought a turntable I had up for sale. LOL
It was not unusual for me just to give stuff away to a friend, in need of this or that. In those days I actually had friends.
Sometimes it was big items that I didn't want the hassle of dealing with, anymore. The biggest was a pair of Acoustat Model 3 electrostatic loudspeakers. I never used them much, having the 2 + 2s, which were better, and took up less floor space. I was happy to get rid of those.
I sold a few things at the 'Bay, but was too lazy to work out boxing and shipping. Shipping a large open reel deck, or a fifty pound amplifier wasn't my thing. And I didn't want to have to deal with an unhappy buyer at the other end, a thousand miles away, if they didn't like it, or if the gorillas at UPS were doing their usual 'throw it off the truck' thing.
During my move to the country I brought a lot of stuff with me, in plastic containers. Don't even ask me why. I rotate some of the gear. Just to look at, more than anything. A lot of items gather dust under the bed. Most wound up in trash bin.
I keep a brace of Dyna Mk-IVs and a tube preamp for winter months, in order to help heat the room. Not much else is left. Let's see... there's a set of Paradigm shoebox loudspeakers wrapped in heavy plastic bag, in the basement somewhere. I'm pretty sure there's a top of the line Yamaha integrated amp down there, also wrapped in plastic. Some DACs and headphone amps from the Full of Schitt guys, ProJect and Cambridge Audio. A couple of MC step up devices from companies no one remembers.
Really, no one wants those sorts of things, anymore. It's cheaper and better just to buy something new. My daughter can garage sale them after I beam up. Make a few dollars, possibly. The guitars will sell for more. Much easier to sell second hand guitars than old audio gear.