That link that dx posted above may well be very helpful in explaining quite a bit for you, and thanks for posting that dx.
When you say you are looking for wholesalers, do you mean actual wholesalers or drop shippers?
While some people do still make money from using drop shippers on sites such as ebay, it can be quite difficult to find your feet when just entering the market.
Buying wholesale will always get you a much better price because you are buying in volume, however a true wholesaler will not be able to give you a wholesale price until they know what and how much of any given product you want to order.
This is a common misconception with quite a lot of new comers to the field of online sales, they look at a listed price without inquiring about volume buying (wholesale), then getting themselves a better price that may well allow themselves to compete.
That being said, there are some genres on ebay that smaller sellers simply have no chance of competing in because they are going up against very large sellers who are very well financed, and ones that buy in such volume that they have the market on its knees.
Another option you may well consider looking at since you are in the USA is liquidations. Now there are a few pitfalls that you need to be aware of when dealing in stock from that market, however it does offer sellers some really good opportunities to make money on ebay.
Selling second hand is another area where you can make good money on ebay, you just need to be in a large enough area to source stock, know what to sell and know how to talk a good deal.
If you would like to send through some specifics on what it is you're looking to source to email@example.com, the staff there will do their best to turn up some buying leads for you to follow up on.
Btw, welcome to the site. biggest tip I can give you from someone who has been in business for much longer than I care to admit these days, don't let frustration guide your decision making.
Some get lucky, walk into this field and start making money, but believe me, it takes most a lot of time researching, turning over every rock they can find till they get a foot hold.
Those that get frustrated usually get out of the market altogether, those that dig in with a little determination always give themselves the best possible chance. Having said that, not everyone of them will succeed unfortunately, no matter how much they try, but this business model, like most, doesn't come with a guarantee of success unfortunately, just have to give it a red hot go!
Good luck with it, and just yell out any time you need assistance with anything at all.
Cheers : )