Check for consignment shops in your area as well, they tend to be a little more boutique-ish in addition to all mentioned above.

e-bay has a special category for "lots" of clothing, where you can pick up multiples of things in one buy.

I get the goodwill thing, I love shopping there, but I live in a big city and regularly find nearly new stylish pieces. My mom lives in a small town and everything at hers seems worn down.