I recently got Kaufman Kona Mulslin at Joann’s. It has 90 inches of width (so twice that of regular fabric) and cost $5.99/yard. I bought it with a 50% off coupon, so it wasn’t bad. If you needed 30 yards of regular fabric, you could probably get away with 15 of the 90 inch width. With the coupon (which they have this week and next) that would only cost you about $45, which is not bad at all!
Cheers!
Rachel