Ah, so you are helping them to make a purchase decision?
Honestly, markings would be the last of my concerns, especially in the breed nowadays.
If the breeder cannot produce hard copies of recent echocardiogram and 24 hour holter monitor results, read normal by a canine cardiologist, can't produce vWD and liver and thyroid panel results, OFA hip results, elbows, CERF, and a few other pre-breeding health screenings, on the parents, then I'd advise your friends to pass.
Beyond all that, the pedigree should be a thoughtful one, with causes of death known in all ancestors, age at death, and the pairings aiming toward good structure, health, temperament, and longevity.
While I can find something great, and something to love, in most every Doberman out there, I sure would NOT give money to anyone for puppies produced in a less responsible manner than that listed above.
There are a ton of poorly bred Dobermans in shelters and rescue who would LOVE to get a good home--if one is going to obtain a poorly bred dog, then that can be done while helping animal charity, rather than lining the pockets of those creating the problems.