for higher price morph ball pythons, which usually aren't in local pet stores, you pretty much have to get online. some of these animals are bought for thousands of dollars, and shipped to the new owner. so a normal male is going to be alright.
you best bet is to find a breeder, some one local would be good. talk with them and get to know then a little. ask around the forum, there is a great feedback/inquires section that you can learn alot from. also the Board of Inquires (BOI)- is a larger groups of threads that deal with breeders all over. heres the website: http://www.faunaclassifieds.com/foru...splay.php?f=13
once you get to now a breeder and have some communication, that hardest part is going to be waiting for the day to come when a box shows up on your door.
it's your snake, so it's your preference. if you think the pet shop has been a good home for the snake and it is as healthy as it could be , then go for it.
another little note... you could also find a reptile expo or show in your area. there are tons across the country, and there will be plenty of ball python babies, yearlings, normals, morphs, rodents, the whole 9 yards. if you have one remotely close to you, i recommend going. even if your not buying, it's great to see everything that out there.