A new whirlpool front load choked for a customer. The "filter tray" just before the pump had a couple of dollars and a big chunk of change. It also had a nail set that chewed his impeller. that cost a bit more than I found.
I've come across jewelry, the best was a gold baby bracelet - not worth much, but the owner was stoked - it was a family heirloom. Lots of rings, time to time.
I never keep the stuff. I just use it to hold down my bill.
I've ran cleaning businesses, Hauling, and handyman businesses. I've found some good stuff, esp. on the hauling. Times are tough these days, people won't pay for you to take their trash. But that's how I got into appliance repair. People pay me to get rid of the appliance, and I'd dig in and fix it, then sell it. Money up front, and on the back. Nice.