You can buy from anyone who sells Maxxis tires, however keep in mind that shipping on a case of tires can get very pricey.
Im a dealer but id recommend buying from someone more local to save money from having to be shipped.
A case of 9.00 for example is approximately 48 lbs., but shipping on a box that size goes by box size and not weight. That puts it at around 100 lbs., making it more pricey.
Now if you "squish" the tires you can use a smaller box, which is what i do, to save money for customer on shipping.
But its always better if you dont have to pay shipping and can save money.