One year for Christmas I got Ka-Bala, the mysterious game that foretells the future. I enjoyed playing with it (it predicted that my brother was going to play quarterback for the Bills), but soon got tired of it. It either got thrown out or sold for 25 cents at a garage sale.
About ten years ago I managed to find one on Ebay for a little over $250.
A very large collection of 78 rpm records that my great aunt had left at my parents’ house for safekeeping. I thought they were junk and sold them at a car boot sale (like a garage sale but in a field and huuuuuge) for something like £20. She was very gracious when she found out. I felt sick.
In the ninth grade I traded Spider-Man #s 1 - 76 for a pair of Converse Chuck Taylor All Stars. Comics were for kids.
Oh my.
Yep.
Way back in college I happened on a 1607 Hebraic work I gave to a friend who was very Jewish and very religious. I figured it was worth maybe like 50 bucks or something. Turned out to be rather rare and important; enough that he sold it after we graduated and paid off all his student loans. I was happy as Hell for him; I gave 5 bucks for it and he turned it into freedom and a new start - not a bad deal at all.
We’ve never given anything away, but we’ve been on the receiving end. We went to an estate auction a number of years ago and purchased four Robert Bateman framed pictures. We knew they were probably worth a few hundred each (which is what we paid - close to $1000 for all four I think), but we had them appraised, and combined, they’re worth about $20,000+.
We have a couple of other pieces of art that we’ve purchased that are worth at least double what we paid for them too, but nothing as big as the Batemans.
Many years ago a friend of mine was one of the trained monkeys (guys who stands around keeping an eye on things and making change) at an arcade. He would hold back all the silver coins that kids brought him. I’d pick them up at face value.
My grandfather sold 5 acres of riverfront property and a ranch house with an addition and connecting breezeway for $80,000. We told him it was worth much more and so did the real estate people, but he apparently felt it would be wrong to profit too much from it, and since a nice family would be living in it…
The guy he sold it to never moved in, held it for six months, and flipped it for $350,000 to someone who later sold it for $500,000.
edit: This was decades ago…it’s probably worth a lot more now.
My mom sold a REALLY nice upright for $50. She was pretty much The Rainman: Grew up in the great depression and any amount over $20 or so just fell into a big box in her head labeled “Vast Sum of Money”.