You don't want to shop for an attorney based on rates alone. You need someone who is competent and hard working. Additionally, many lawyers offer payment plans. Your charges sound serious, don't hire the least expensive lawyer you find.
He should be worried about this. Even if NY does not extradite, he can get detained and held until PA calls NY to ask whether or not they will extradite. This can happen every time he gets pulled over. He might end up spending a couple nights in jail until NY and PA communicate. Additionally, NY will suspend his driving privileges and NY and PA have reciprocity. Therefore, he will not be able to drive in PA.
The outcome depends on a lot of factors. Most importantly, whether the DA can prove the charges. Depending on the strength of the evidence, your boyfriend might want to go to trial. If the evidence is strong, a well negotiated plea might be in his best interest.
If you received a target letter, it means the federal government is investigating. You need to retain a lawyer that practices in federal court and it is very important that you not discuss this matter with anyone other than an attorney.
Technically your juvenile record is supposed to be sealed but often times law enforcement officials can still see this type of history. You should also be careful not to lie on the police application. Read the question carefully. It might say "list all arrests including as a juvenile."