Here are a few eBay dealers that are a bit offbeat. They're all nice to deal with.
lesliep4819. Her store's name is Ewe-phoria. Nice prices on Noro. Individual balls often available. Excellent service.
lifes_an_expedition. Interesting yarns, imports and handpaints; plus a miscellanea of everything from Guatamalan fabrics to ethnic jewelry.
nana cindy. Mill ends and rejects of Mission Falls yarns, often on huge cones and alwakys dirt cheap.
sanfelipeysantiago. Handpainted pure merino from a South American coop. Lovely soft yarn, great prices.
BaaBaa on Ravelry