I'm an eBay fanatic (does, indeed, work with paypal), and I recently found a seller with the most astonishingly beautiful yarn.
As always on eBay, the prices are good. You may have to do the bidding thing, and you might have trouble getting huge amounts of the same yarn, but she does custom orders, so it shouldn't be too much hassle.
And the beauty of this yarn is not to be believed. I've been working with this rayon chenille that's all variegated brown with a hint of green and red (called "furcoat") and I just want to snuggle myself up in this stuff and never move again cloud9