If I'm not mistaken, the person on here was referring to fabrics they got at Goodwill, not other things. I find cheap, cheap prices on things, for instance, bed ruffles that I can cut into squares and use for foundation piecing for $2.00 for a queen size. I only needed to use 1/2 of it for all the piecing for a queen quilt.
They DO have lots of ugly stuff but I'd also suggest you go to one in the nicest part of your suburbs or town. We have found beautiful clothing for $5 and the tags are still on. There are some really great bargains. My sister-in-law got a first edition book for $.75 and resold it on E-bay for over $400. Not bad, huh?