I believe you can register APBTs with the UKC. How old was mom? She should be at least 2 or else she was not old enough to have her genetic health screenings for hip dysplasia and other genetic diseases common to the breed. breeding is not something to be taken lightly, the dogs need to be better than those that an be found in a shelter (and there are NO shortage of APBTs in shelters). That means the dog should be shown or judged by a judge to prove he is the standard for the breed. this page tells you how to know if your APBT is to standard (keep clicking on step 2, step 3...on the bottom of the page) but a show judge should really be the one to tell. This makes sure your dogs actually look like APBTs, something many shelter dogs cannot offer. The dogs should be health screened so you are somewhat confident that no problems will be passed down health wise, another thing you cannot get from a shelter dog. Finally you need to make sure your breeding dogs have a good temperament, one that is true of APBTs, so it is best to get them their CGC or get them therapy dog certified as APBTs have a very human friendly temperament. That is another thing that cannot be guaranteed from a shelter dog. If you cannot or will not do these things then I'd urge you to stop breeding dogs, the world really does not need any more shelter quality pets, we have LOTS of those already, being killed daily. I would spay your girl as soon as she weans her pups. If you do these things sorry for sounding like I think you do not, you do not sound like you are very prepared which leads me to believe you are not experienced.
I would bring them to the vet for their shots, they should really get a full exam not just shots. I'm not sure of the age, call your vet and ask. price will also vary you'd need to ask the vet.
You do not have to crop the ears, it's up to you and the owners can do it as well but the standard says either works. Tails are not docked in this breed so there is no reason for the price to change (see standard:
United Kennel Club: American Pit Bull Terrier )
Price is of course your decision. Remember pups need to stay together and with mom until at least 8 weeks, 10 weeks is preferred.
Good lick with them and sorry about the 4 dead pups.