Magnum 360 crank balancer

I just had the machine work done on my 5.9 Magnum. Stock rotating assembly with .030 over pistons. I'm leaving it externally balanced and just had him check and make sure everything was in order. Using a McLeod flywheel with their 5.9 weights and the stock balancer.
Have you got a price to have it changed to internal balance? My guy said could be $600-800.00 depending on how much mallory he has to use.
B&M makes a flex plate to use a neutral balance convertor on a 5.9.