From my location (near San Francisco) I've been ordering from Dick Blick, taking advantage of their occasional coupons and free shipping.
Another secret weapon I've recently developed are my kids. I taught my twelve-year-old daughter to use the Logan 650 (very quick study) and my ten-year-old helps with cutting bards down and general assistance. We cut sixteen mats with backing board last Friday in a little over an hour. For some reason I go insane trying to cut mats so this has worked out very well for me--the cuts are perfect.
Dick Blick has also been good. One of the boxes of 25 full boards came in with a serious ding and water damage. Most of the board was still usable. They told me to keep it at no charge and sent out a new one--they had just changed to better packaging, too.