Honestly, if they are so eager to get rid of the puppy he is better off with you. That is how i feel. When i got my puppy this house was disgusting and they gave me whole milk to give her with her dry food. They are not suppose to have whole milk. Even though the puppies are not supposed to be taken away this early it might be for the better since the family did not want him. I had to feed Daisy through a syringe at first and the vet now says she is completely healthy. Now two weeks later she eats the formula out of the bowl and she eats more (first it was only two syringes and now its three).
That is just my thought. Even though its going to cost you more than you expected, it will be worth it in the long run. I have a health plan with my vet and its not bad to get all her shots, diagnostics testing, comprehensive physical exam and unlimited visits.
I wish you the best of luck with him
he will bring you lots of joy when he gets stabled on his feet