You weren't getting nagged for asking about the price of pups, you were getting nagged because someone who is breeding a dog needs to do a LOT of research prior to breeding. By the time someone is TRULY ready to breed a dog, they should already know what the going price is for a pup.

Breeding dogs doesn't make much money if done properly, as there are a lot of medical tests to be done on both the male and female dog to be bred, researching the bloodlines of the dogs, etc. This is why properly bred purebred dogs cost so much. Not because the breeders can make money, but more so the breeders can cover their costs.