You never know with eBay, it may well be that you are finding either wholesalers using eBay to sell direct or possibly very large wholesale buyers selling on a very thin margin to create turnover and generate profit that way. Of course I'm just guessing, there may well be a wholesaler that can give you a better price than you can find on eBay, but ultimately that's going to come down to how much you buy.
Shott an email to Link hidden: Login to view with your request and support will see what sort of leads they can generate for you to follow up with. Just bare in mind that when following up, do it via the phone so you can speak directly with them and discuss order volume. Chances are that you aren't going to find any wholesale prices on their websites.