Reliable/Good Transmission shop for rebuild/diagnostic?

Hello there all,

I am a young college student and live in greenpoint but dont mind traveling to get this done for cheap.

I have a 99 buick and the transmission on it is slowly dying the way i see it. I would either need to get some parts replaced or just have it rebuild as a whole.

I'm looking for a decent shop that does transmission work and wont rip you off.

A physical diagnostic would be nice to see if i need rebuild or just few parts.

ANy suggestions?