Where can I find cheap black tights?

I'm aware of the obvious places (American Apparel, department stores, hue.com, mytights.com, UO etc) but I'm trying to find super-cheap tights (<$10) to stock up on. I don't really care for the quality, as they'll probably be quickly destroyed but they have to be solid, opaque black (AT LEAST as opaque as this, but preferably more a href="http://store.americanapparel.net/rsaph.html#i)," rel="nofollow"http://store.americanapparel.net/rsaph.h…/a with regular tight texture (none of the ribbed stuff). I've looked at F21, but they don't seem to have opaque black tights at all, only sheer ones.