All the pet shops I've ever been to don't even sell dogs, because its inhumane to keep them that cooped up, and the cats they sell are through a connection with the local humane society. I don't know if I've just been to really nice pet shops or what.
But yeah, dogs are hella-expensive. Especially if you want to buy from a licensed breeder. Which I don't even get why people do, cause purebread dogs have way more health problems.