You don't mention what quantities you are buying -- in my limited experience one of the problems with phone/online ordering matboard is that it is very dense and heavy and small quantities are apparently too difficult or expensive for some suppliers to package well. I have seen a few sources that won't sell less than 10 or even 25 sheets of full size board. I've been using Crescent museum board from Blick's (which I examine and hand carry from a brick and mortar store) but it's more like $15 for a 32 x 40 sheet (and has been rising steadily in price the last few years).