Didn't know these were that popular outside of Denmark. The thrift stores here are always flooded with B&O equipment, to a degree where i suspect they dump a lot of it.
A thrift store is not my source for this, but in Columbus we have the best ones, imnsho, in the country.
A couple of years ago I got a Contax T2 for $13 and a 35mm Rollei slr for $9.
The Contax T2 was a deal... the Rollei SLR, you probably paid about the right price for it Lenses were great, but the bodies are horrendously unreliable and if they break, they're instant bookends as they essentially can't be fixed if it isn't something like the film rewind knob coming loose.
I find my best deals in pawn shops around these parts. The thrift stores are horrible and usually have the stuff no one wanted in their homes. I would love to find Contax and Rollei cameras in the thrift stores.
I don't get that stuff very often. Over the past 12 years I've found some very valuable bargains. Akai GX747 for $60. Netware 6.22 bump disk for $5. Minolta 100/3.5 macro, looked like new, in its case, for $15. Minolta 58/1.2 for $9. Columbus is a white-collar city so the pickings are good. We live in a middle-income neighborhood but wife and I are small town folks (mine was just over 700 and hers about 1500). So we look at what people put on the curb. Got some nice Lenox china one afternoon, most of a set. (It makes us sick to think of what people throw away.)
I don't suspect they would show up in US thrift stores either, i reckon B&O is considered luxury. It IS good hardware, no doubt, but we're rather flooded over here.
Just last saturday i scored a Rollei enlarger with El-Nikkor 50:2.8 attached to it. I had to cough up with the pricey sum of 50 danish kroner, equivalent to 8,5 usd. I also got an Olympus XA for half that price. My wallet suffered immense losses that day.