I'm sure. Those are probably big name pet stores. Even the biggest LFS/LPS doesn't sell more than 10 plecos of one kind, that I've seen.
You're best bet is contact exporters from where the fish are being shipped from, like Singapore. Again, you would have to buy probably like 100 fish. Then you have to calculate the shipping costs and duties. More than likely, these places will not sell you a larger amount UNLESS they know you will be constantly buying more fish from them. Like they would probably want you to buy like 100 fish every few months or so.
I know you're trying to get a good price on plecos, but the best places you can get them are from other breeders.