1. Most wholesalers require that you purchase things in bulk quantity, so you may have to buy more than you actually need.
2. Most wholesalers require payment up front, as opposed to receiving things on credit.
3. Many wholesalers have a minimum purchase, meaning that, if the wholesalers minimum purchase is $500 and you only need a few things, you'll have to buy more items to reach the minimum purchase amount to have your order shipped.