First of all, let me state that I have been a breeder of AKC show Beagles for 10+ years.
What you may not know is that the breeder has expenses you may not have considered. For example, my wife whelped a litter of five puppies Saturday night. She was up ALL night. She will sleep on the floor in the room with the puppies for the next two nights to make sure the mother(bitch) does not lay on them by mistake and smother them.
This litter was the result of a breeding to Best in Show stud dog. The stud fee was $1000. We had to fly the bitch roundtrip to NC and back($350). We took the bitch to the vet to be X-rayed last week($150). We will be giving shots and micro chipping each puppy($50+). The food we feed cost $45/bag. What I am getting at is we will need to sell two puppies just to break even. With past litters we had to have emergency C-sections at 4am in the morning($1500).
Good breeders are very selective who they breed to. We are trying to improve the breed, not just sell puppies for a profit. We will not breed to or with anyone who has genetic defects in their line. If we end up with a dog/bitch we some problem we have them nuetered or spade. For these reasons we sell our puppies for more money. In the long run(15 years) our puppies will cost you less because our careful genetic screening. One extra trip to the vets office can easily make up the difference in the original cost of the puppy.
Also, the reason good breeders are very selective in placing their puppies is from experience. We will take back any puppy we sell , EVER. We have had people tell us they lived on 2 acres with a fenced in yard. It turns out they lived in a condo and their neighbors complained about the barking. We typically will not sell a puppy to someone with small children(3 years or less) because these people have their hands full with their kids. We will only sell puppies to someone with a fenced yard.
A great Dane is a very large dog that needs room to run. They were bred to be guard dogs. The breeder wants to make sure you are prepared to handle a breed like that. They do not want to get the puppy back when it is 4-6 months old.
That is why they/we are so selective who we sell to and ask a lot of questions. We typically have no problem selling our puppies and always have a waiting list. Most of our sales are referrals and repeat buyers.