Recently Marianne Fons was on Simply Quilts ( It was probably an older show. ) and she answered the question of how much fabric should one buy?
I loved her answer, and hereby pass it on (paraphrased) for those new quilters among us.
Alex Anderson: How much fabric should you buy? Marianne Fons: I buy enough to do a washer load with it. *grin*
Hope this helps, Elena in Tx