I think you can look at them and tell whether or not they are of quality. Take a clutch of the same morph. Some will look better than others a lot of the time. Those animals stand out and cost more. Buyers have the option of choosing the better looking animals and sellers have the option of charging more money for the better looking ones. "Looks better" is what we are talking about here. It's the paint jobs people are paying for. That's why you can buy an uber healthy normal for 20 bucks.