Charities through the years, often in the thrift shop section.

Pricing is an absolute nightmare.

While some places are pure evil (habitat in Wyoming), others struggle to at least try to get it right.

A working, mechanical KA stand mixer with SS bowl and paddle, nothing special like bowl lift or unusual color, should go for about $30-50 around here. I see them priced everywhere from $15 to $200 at the same store, depending on who did the pricing. 

I always feel free to talk to the manager. If I'm reasonable and polite, nearly always they will agree to a price more in line with ebay.