Depends on what you mean "buy"
If you mean cash, you're less likely to get any takers. However if you're willing to trade/take credit, you might want to check Forest Lake Pets. There was also a store just south of 10/169, I can't remember the name of it but it was run by a nice woman (whom had a couple huge tortoises wandering around the store) who also might be approachable.
This was a couple years ago, I can't guarantee they ever did take fish from local breeders, nor what their policy might be now. I do know that both were interested in giving me store credit for various plants.
As Overstocked mentioned, sometimes taking fish from local breeders is risky. I've heard horror-stories of one bad bunch of fish knocking out an entire store's stock. Of course they should have used quarantine tanks, but the "local breeder" gets the blame and ma&pa storeowner no longer take fish in from anyone but licensed breeders for "insurance reasons."