Well, first I have to admit by trading I have the radio gear I mostly want and the bottom line will be good when done.
We're not talking a fortune but in a year I guess I have turned $40k in amateur radio gear. Out of that I get to keep about $10k worth of quality stuff. Damage to my back account, about $2500 to the good.
But sheer idiocy. One guy I just spent a fair bit of time with laying out all the components I have for a popular line of antennas called Hustlers. He has an ad, long running IIRC, asking for systems made by Hustler.
So I laid out to him my kit (quite good and anyone would be pleased to own the whole kit) only for him to respond he was interested, if he could CHERRY PICK. Imagine that, he wanted the impossible to get parts I had and pay me 1960's prices. It's actually funny. I would be left with a pole, a few feet of coax and one resonator for a band that's barely active at the best of times. LOL.
Another guy would email me literally every day to ask me if I had dropped the price on a specific radio as it did not sell that day. This went on for close to a month. Every day, email from buddy asking me if the price dropped as the radio wasn't moving. I had no witty reply for this guy but I thought, he must have a serious interest for emailing me daily.
Finally, about day 25 he makes an offer of literally 50% of my asking price. That is an outright insult in this world. In a flash a brilliant reply hit my brain, "I suggest if you don't like my price you buy one of the non-existent identical radios on {SITE REDACTED} to mine." Funny enough, I never heard from him again after that. I do suspect he got a straw buyer for the radio. It went to the same town as his, the offer came in 2 days after the email, and I never saw a wanted ad from him again.
I have a ton of additional stories of all stripes. I know I won't quit, I do have fun occasionally and get to play with expensive radios and other equipment I would never consider buying for myself.
I used to trade in guitars in the 70/80's then got out for a bit and when I got back in 63 stratocasters had gone from $1000 to $30000. Too rich for my blood.