I have had good luck buying online. I have only had a problem with 1 shop charging me for fabric, sending me a shipping confirmation and then I never received the fabric. I emailed and emailed and never a response. Finally the money was refunded to my account but they still never answered any of my emails.
I stay mainly with shops thru the Fab Shophop and Quiltshops.com. I do like Thousands of Bolts and my new fav shop is one of our board members-Rocking Chair Quilts.