$500 may seem like a lot to most folks, but maybe not to wholesalers, especially if it's a one-time deal. If you want to buy that many plecos, why don't you try making a deal with your LFS, offer to pay cash. I'm sure they will give you a discount. I don't know the exact definition of a monopoly, but it's when a single company owns or controls the entire market for a certain product. For example, Microsoft is as close as possible, if not already a monopoly in terms of software. So in your case, a monopoly would be one wholesaler that supplied every LFS. Or a single fish store or company, like if every LFS was replaced with a Petco and nothing else. In this case, Petco could charge whatever they wanted because they have no competators. Why don't you look into getting a resale lisence. Then maybe the wholesalers would have to sell to you. But, even if they did, I'm sure there is a minimum to fill with each purchase. Hope this helps.