Hi Victoria. The reason that you see so many items selling at prices lower than you see on the wholesale sites is because the people are either getting them through liquidation sites and closeouts, or have enough capital to buy huge bulk orders.
Keep in mind that most of the stuff you see listed on ebay is actually selling at below wholesale prices..
You need to check places like 'liquidators.com' and 'surplus.net' if you want to get items (in bulk) at prices you can resell on ebay for a profit..
Most people who are selling through those venues are selling large quanities of the items, so they only have to make a small profit on them. For example if you could sell 100 widgets per day, and were making 3 dollars profit per widget, that would be acceptable. But if you could only sell 10 widgets per day, you would have to have a much higher markup price on them..
Alot of the people you see selling are running dozens of auctions per day and some hundreds, They only need to make a couple of dollars per item to be profitable overall...