Prices for purebreds vary greatly across the country and depending on the lines and quality of the pup.
Good for you for knowing NEVER to buy a dog from a petstore. These dogs are purchased from puppy mills where the conditions are deplorable, the genetics are not considered and genetic and other illnesses are common. However, while a reputable breeder will test for genetic conditions like hip dysplasia and cherry eye, testing is not an indicator that a breeder is reputable. There is MUCH, MUCH more involved in being reputable than a few genetic tests.
I recommend you spend hours researching what makes a breeder reputable. There is so much to learn before purchasing a puppy.
And in the end, I would recommend unless you need a purebred pup for a purpose (ie. herding, hunting, etc.), I would strongly recommend you go to a shelter and get a shelter pup instead. There are plenty of bulldog type dogs available in the shelter systems and breed rescue groups. Go out and save a life instead of paying hundreds and hundreds of dollars. :)