Unless you're one of the major players who can (and do) pay in the 6 figures for the latest and greatest morph, the main cost of these animals isn't buying the snakes themselves it's feeding them and housing them year after year. And if you're overpaying for something basic like bedding it's going to add up very quickly.
OP, if you have a farm supply store in town they might be able to special order bulk bags of aspen as well. Many of the big feed producers have lab supply divisions, so they might be able to order you some of their brand of aspen with the feed shipment so you don't have to pay the shipping cost.