A thrift store. Not derogatory, used only to describe the general low prices of resold/donated items with a convenient rhyme. Can be used to describe national chains like Goodwill or local thrift shops and sometimes surplus/salvage stores.
1) "Hey, where'd you find that copy of Chibi Robo? Aren't those kind of expensive?"
"Yeah, I got real lucky at the poor store last time I went, guess someone donated it."
2) "Dude, you should come with me to the poor store sometime, there's always cool stuff in there. I bought a bunch of out of print books for way less than a lot of eBay listings."
3) "That's a snazzy suit, where'd you get it?"
"You'd never believe this, but I got it at the poor store! It's amazing what people will get rid of."
4) "If you're looking for old vinyl records, chances are you can find some at a poor store, I've found several at good prices that way."