There are several reasons that you pay more for Bulldog puppies.  The primary being the fact that bulldogs are not easy to breed.  It is rare to find a male that can naturally mount a female (due to body structure), and a female that can whelp her puppies without a c-section (due to big heads). The mating is then achieved through artificial insemination.

What this means is there is several steps, and a lot of veterinary expense, and special paperwork,  just to get your female pregnant..There is a great deal of time, effort and expense involved in raising a Bulldog litter. It can easily cost $2000 - $3000 to breed, deliver and raise a litter, without consideration for the time invested. Many things can go wrong and the cost of a litter can be more than the money the puppies are sold for if there are health issues and complications especially if there are only a few puppies born to the mother.  

This is a special breed which requires the help of a human to bring a litter to eight weeks of age.  In spite of their appearance the Bulldog as a puppy is extremely fragile.  It requires constant monitoring of the puppies 24 hours a day 7 days a week.  You are home from the vet with mom after the c section and the puppies are starving so now starting every two hours twenty four hours a day seven days a week the puppies are put with the mom to nurse.  And that is if mom has enough milk, if not then its time to buy puppy formula and make bottles.  If they do nurse then the puppies are never left alone with the mother.  Bulldogs do not make the greatest mothers as they may lay on or step on a puppy killing it without even realizing so this is why they are not left together.  So in between feedings you are constantly washing bedding for these babies.  After a few weeks the feedings can be spaced out and you can get a bit more sleep if you can remember what that ever was like.  When the puppies are old enough then they need to be dewormed, microchipped, vet checked, vaccinated, weaned from mom, and new homes lined up and people chosen that will receive one of these special little bundles that I have been responsible for their very life and helped raise and bring into the world. Bulldogs are not like any other dog. Unfortunately, this amazing look, personality.... everything that we love in the Bulldog, has been bred into them for hundreds of years and has resulted in a dog that can not breed or whelp naturally, tends to have smaller litters and sometimes health issues.