I agree with feline fanatic about Golden Lane! It's less than 1/2 hour from my home, so I am able to visit often. It is not a typical quilt shop, as it is a Mennonite store. Ie, in a metal pole barn type building, not decorated - and the lighting isn't great. Ada, the owner, is a really interesting woman. She doesn't mind of you take a bolt to the door or window to see in better lighting.
Prices when I was there a couple of weeks ago were all under $9/yd.
If you are going out of your way at all, I'd recommend calling ahead to make sure a shop is still open. Many that are still listed in google searches have closed, unfortunately.
Will you be driving right along the coast, or inland, and how far? I stopped @ The Crazy Cousin in Fredericksburg, VA (not far from Washington, DC) in the spring. It is a wonderful shop, but not for a quick stop!