Hi Norm,
Nice looking piece of kit I must admit.
Have to say it's probably a bit pricey for what it really is and would only pay its way if you were using it as part of a business, but not as an owner user. As far as what it costs I don't even know anyone that does it as part of their businesses. They just do straight grinds and reassembly of the machine.
Back lapping is one of those things that many owners do themselves on their own machines by utilising the compounds that are available on eBay.
Sorry I can't be of more assistance on this topic Norm.
Cheers,
BB.