I bought a Boss 302 new off the showroom floor in 1969, and sold it 10 months later to get money to go back to college ....
But, on topic, I let an aquaintance talk me into selling him a couple pairs of vintage speakers at a very reasonable price. With a fairly high level of sellers remorse,I tried to buy them back several times over the years but was rejected. He finally said "yes" but won’t accept anything less than market value for them. I’m hanging on to things that are difficult (impossible) to replace these days. That’s a good formula for collecting "too much stuff".
And, yes, I deserve any criticism I’ll get here for being a "softy" and trying to be accommodating to a "friend."