It boils down to like others said, if you are doing it to breed or just to keep as a pet. Some lines may give you better patterns, but if you're not intending to breed then you can spend a bit less and get something else. Then you can look at the person you're getting it from. If the person you are getting it from is shady, and keeps them in some pretty bad conditions, you could risk bringing things into your collection.

I would pay a bit less for a morph that's not as higher color/pattern quality, but I would pay more then I would even as just getting a pet.