Many eBay sellers purchase wholesale items, and resell the same items in their auctions for a profit.
Locating wholesale suppliers takes a little work, but they are out there. Wholesalers usually are one of the better sources of products to sell in online auctions.
While many wholesalers require that you have a Certificate of Resale before you can purchase merchandise from them, there are some who don't. Even if you do end up needing to obtain a Certificate of Resale, they aren't difficult to get and depending on the state you live in, don't cost that much.
These are a few sources of wholesale information online:
National Association Of Wholesale Distributors