Do you really want a merle pit bull? They are great dogs and not all have problems but keep an open mind and know what you could be facing when making the decision to purchase one!
First off I will say I do not suggest a merle pit until you have done some research on it.. They are pretty but health wise it is not a good decision to purchase one. People are charging extremely high prices for a pup you will end up spending nine times more on because of genetic health issues.
The pup could have problems with any number of things such as the skin, eyes, and hips. Don't go into any purchase blind because you might end up with a blind pup or worse. Check out the links provided.
Are you aware of the fact that the ADBA and UKC will not allow a merle pup to be registered? I have heard breeders say they can get a pup registered with it being merle, they are being deceptive with this. They are not reporting the correct information on the pup, they have probably just reported it as being either brindle or of a solid color. Don't be fooled by these deceptive people.
This link below shows research that proves that the merle gene is associated (the cause of) dogs being deaf. This has been proven to be proven true for 85 different breeds (pit included):
This link below is mainly in reference to collies but it explains the merle gene and how it effects certain disorders:
This picture above is of Isis a blue merle I owned. Isis was a wonderful girl and didn' t have many health problems but as always there is two sides to every coin. You can be lucky enough to have a healthy merle but there is always the possiblity of things going wrong. If you are going to purchase one I suggest researching info on the merle and of it's parents before making that purchase. NEVER BREED MERLE TO MERLE!!!