My goodness, I thought those prices were low! I sometimes paid higher prices wholesale for linen, and much depends on the grade, quality, width, and weave. Linen will far outlast cotton, can be burnt or stained and will bleach white again, and can only be surpassed with durability and strength by hemp cloth.
Two months ago we received our first JoAnn's super store, and while there I noticed some fantastic linen bolts, in a wide range of colors and weaves, and all at very reasonable prices, sometimes phenomenal prices! Even better if you use a coupon!
Honestly, I'd not be too upset paying $15 a yard, it's very cheap IMHO, and even in this low economy.