The only problem I had was when I bought a fabric panel. It had a flaw on it and when I emailed the seller about it, she said it wasn't there when she mailed it to me, so I must have done it. She also made a remark about people who shop Walmart fabrics. I see that now she isn't selling on ebay anymore, unless she changed her name.
Otherwise, I have not had any other problems. Just check their ratings and I always check their postage. Sometimes I think they try to make up on shipping for the great deal they offer on the fabric.