Ugh.... hets
This is just my opinion and it is as follows.
When selling hets I include a print out with the snake including a photo of the snake being sold, BOTH parents and documentation of the clutch.
Example:
Het Pied Male #01-005
Hatched 5-17-2010
(photo of snake being sold)
Parents
Pied Male
(Photo of male)
Het Pied Female
(photo of female)
Clutch ratio
7 eggs: 1.1 pieds 3.2 het pieds
(photo of full clutch)
Now I know not every breeder can take the time to do something like that. When buying hets I look for a few things:
Does the seller have any visuals of the morphs he is selling het for?
If not what documentation/guarantee is provided?
If seller has no visuals or proof and the documentation/guarantee is shoddy or nonexistent, then I move on.
If the seller has a very good reputation (example NERD, VPI, or other
VERY well known breeders) then I will make exceptions to the documentation.
Also if the entire clutch is present and for sale (let's say corn snakes) and I can see anery, amel, and stripe then I may buy one of the normals knowing that I've seen the clutch and it's most likely a het.
Price also plays a big factor when I am looking at hets. If I am paying $1000 for a het "New gene X" ball python then I will look for more proof since it's new rare morph that not many average joe might have. If I see Jimmy McVendor down the row selling "het gene X" for $200 I really have my doubts about the legitimacy of those hets.
Hets are in many ways a calculated risk. You have to know going in that there is a little bit of luck being tested. You may hit the genetic lottery or you may get a big pile of normals.