Not to bad of an idea, but.
Buy the time most of the balls get to the pet shop they have been gone through by alot of people, and most if not all possible morphs have all ready been taken.
That said, some do make it to the store,from time to time, and If you see one grab it right then and there.
As to what morphs get confused, I can't realy say I'm kinda of new to the ball python morphs, and I can't tell a yellow belly either, It's kinda cool to know I'm not the only one.
something else to think about. All the genes for all the morphs had to come from the wild at some time. In my mind it would be a BIG mistake not to think/know they could of bread in the wild. I'm sure there are het's out there, It would be a 1 in a million shot to actually get and breed one but they have to be there.
Anyway if you do get some you think are morphs, Make sure to find out from someone who knows before trying to sell them, If that is what you hope to do.
Good luck, and post some pics if you get any!!
Have a good day!