I don't trust any of the cheap fast-fashion on Amazon, but I love it for stalking quality bras. I've gotten some Panache and Freya ones for under $20 with enough patience. I've also found that sometimes 6PM lists their items on Amazon as well, which can get me that sweet Prime shipping as a bonus. (The same also applies with stock on Fabric.com, though you can only by the whole yard!)
I do also love Amazon for clothing storage though! Some of my many favorites include a really solid scarf rack and the savior of my sock and underwear drawers.