I used to love the bargain bins section at my used cd store, it was always filled with cheap gems. Granted I spent a fair share of time listening to some crap, but it was worth it to find an old song that was quality.
Also, I'll never touch the bargain bin either because there really are no cd stores around anymore, except Best Buy.
I love hitting the bargain bins at video game stores. There are many many games which don't merit spending $40-$60, but have some redeeming quality at $1-$5. I've found some of my favorite games that way, and the junkers are easy to trade back in for credit. The great ones generally were just obscure and deserved better market attention than they actually got.