Though the turbine shaft can look scorched it remains fine. If you run your fingernail along the shaft and detect a ledge at the location where the bronze bushings ride, this indicates wear. You can typically detect down to 0.001" maybe even a half thou if you are used to feeling for it. If you have a caliper or micrometer compare the area where the bushings ride versus the center of the shaft between the bushings. (I seem to recall that the KKK shaft is o.3750" - 3/8") The center is a non wear area which will be original tolerance. Up to a couple thou (0.002") or even a little more wear is fine.
You also need to measure the bushing bore in the bearing housing. I believe it is supposed to be 0.625" - 5/8" (must have been an imperial dude that speced the sizes for KKK!) Again, compare area between the busings for non wear size. You will need to find somebody with a pin hole mic or telescopic gauge. Any machine shop would do it for you if you just ask.
Unknown to most, the bearing fit on a turbo is very loose in order to create a significantly thick oil blanket on the ID and OD of the bushing which acts as a cushion for absorbing minor imbalance. One or two thou wear on the shaft is irrelevant when considering your dealing with 10-15 thou clearance.
KKK bearing housing overhaul kit I bought out of ADP Distributors in Vancouver was under $90. I also bought a new bearing housing which was $110 and I think ADP brought it in from Toronto. They can also supply compressor wheels, but your quote of $200 sounds normal from what I recall.
Look in your phone book under "balancing". Call any shop and they will refer you to someone with turbine balancing gear. Years ago there were two shops here that could do it, probably more now.