I have bought only larger lots because I had nothing except for the small amount we can buy over here. I then fill a box or suitcase with fabric to bring back to Poland with me. Usually as long as it was cotton, I was happy, since I really did want a stash to work from.
I've been pleased, generally. Just look carefully at the pictures and make sure that the feedback of the person shows that the person isn't misrepresenting things. Sometimes, if you are the risk taker type person, you can get a good deal from a new seller.