Serious breeders that are working on some kind of selective breeding program will probably never have pet shop versions of what they are breeding. I may have a pet shop guppy if I breed angels but at that point would probably not have a pet shop angel. One of the places that cull fish go is right to the pet shop. Generic fancy guppies and culls from a good breeder's work will be much the same fish. Most pet shop fish are from huge farm type operations where nobody really takes the time to select the best breeders. They will select "good enough" fish to breed and dump the progeny into fish shops all over the world. The difference would only matter to a breeder that is breeding show quality fish, most of us would not notice the differences that these guys are looking for. Since few of us are willing to spend a small fortune to buy a show quality fish, it makes sense to breed "good enough" fish on a large commercial scale where they can pass on the costs in prices we can afford to pay. As an example, a decent show quality breeder betta can easily go for over $50 but you can buy a nice looking male for less than $5.