Here is a good one:
http://www.thesheepshedstudio.com/rovingbusiness.html
These are mill end rovings for 7.50/lb. I ordered 2lbs of white and 1lb of the black and white, they also sent some of the brown and white as a sample. The wool is soft and silky, takes dye beautifully and I have yet to find any vm. It is mostly shorter lengths of one to three yards, not one continuous ball of roving, but I don't consider this to be a problem. It is a great deal for the price.