How much are the shots for pit bull?

The same as any other dog; $20-$35 each, at the vet.
You can purchase most vaccines except rabies on-line or at a feed store for $4-$11, which may or may not include the syringes, and of course, you'll need to learn to give them yourself, which is fairly easy to learn.
However, rabies shots can only be given legally by a licensed vet, so you will have to go to the vet for that, or, you might be able to find a rabies clinic near you, were shots are administered(usually held annually by your local animal shelter/SPCA) for $15.
Remember that your dog only needs a 3years rabies shot, not annual boosters, and Distemper usually lasts longer then it is said.
Lyme shots, although you may have them done to your dog, are not necessary.
Do it once, perhaps; it will cover your dog for 3-5years.