Thanks for the answers.... looks like 3 yards is a good average. In this particular sale, I could get three yards for about (or even less than) the regular price of one yard! Too tempting to pass up. As I said in my original post, I don't see myself attempting anything larger than a baby quilt. Mostly I will do small projects like table runners, placemats, bags, wall hangings, etc.
Thanks again for all the helpful and thoughtful answers!