Back in the early 80s, I was teaching piano & guitar at the little local music store on Saturday mornings & Tuesday nights.
This farmer from several miles out of town brings in an old Martin (late 50s, but exact year escapes me.)
Said he finally broke a string, so needed new but said "I don't want to spend too much on it."
I told him strings were $3 and I'd put them on for him.
So, between lessons I changed the strings, stretched them a but, tuned it, let it sit, after next lesson, tuned it again.
He comes back about 45 minutes later and he thanked me profusely.
Then, he says "I've got an old electric, and I haven't played it in years. Can we put strings on that, too?". I told him sure & I'd see him Saturday morning.
He shoes up with a Fender case. I open it. 4 strings on it, plenty of dust, but............
It was a BROADCASTER! Near mint. And get this; the neck was straight. Didn't even need a rod adjustment. Serial number 132.
He says, "I probably should sell it. I haven't played it in 25 years." He asks if I'm interested and says he'd take a couple hundred bucks.
I tell him, let me keep it fir a week. I took Polaroids, and the store owner sent them to Gruhn in Nashville.
They called a few days later, we got a call. Gruhn said they already got an offer of $15,000!
We called the guy & he said "Send it to them."
About 2 weeks later, he comes and picks up a check for 15 grand.
The next Saturday, he walks in with 2 checks. One for me, one for the store owner. $2,000 for me, a grand for the owner.
He said he knew I could have given him $200 and pocketed $14,800. For our honesty, he wanted us to share in his good fortune. Honesty was, indeed, a good policy.
Now, I see these things going for $60,000-90,000.
He died 10 or 15 years later, and his son got hold of me asking if I wanted first shot at the Martin. But, they now knew enough to have called Gruhn and knew what it was worth. I passed but wished them well in selling it. I didn't want to spend that much on a guitar. I had synthesizers to buy!