here in the Chicago area, I use Midwest Engine Tech in Mokena, Illinois...very good work and build an awesome engine no matter the make...they use a CNC crank balancer ..

the last time I had work, it was 350 to balance the lower rotating assembly...may be higher now....

like said, forget about costs as long as they are within reason, when dealing with great machine shops..

I recommend Midwest Engine Tech..

I know you are on the east coast so a local guy is your best bet..