This is a fun experience for the kid (9 and up) and me - but we're not going for the more sought after treasures. He got his first skateboard there 99 cents. I've found oodles of good popular books and cool textiles. He also got an old gameboy for $3 that would fetch a hefty sum on ebay. One time we got a GT snowracer for $3 - can't even get that on Kijiji.
It's fun if your life doesn't depend on it and we usually go a few times a year for a treasure hunt.