So…PMB did the rebuild but White Post finishing? Not sure I understand.
Regardless is this less or more costly than just replacing the calipers?
I had a problem with the left rear caliper not releasing and researching here, I concluded that the brake hose was the problem. I decided to restore all brake components since it had been 25+ years since the last caliper and master cylinder rebuild. Booster and proportioning valve had never been done. I also wanted the calipers in the original finish as mine were painted black.
I shopped around for pricing at the usual places Auto Haus AZ, K & K, Millers, MB classic, Pelican etc. I discovered that these places did not sell all 4 calipers, usually fronts or rears but not all 4 and many did not have the original finish but I assumed that they were selling all rebuilt because they all charged a core charge. Prices for the calipers depended on whether they were the fronts or rears. Prices were like $300+ to $400+ each for ATE. I then decided that i would just have mine rebuilt.
I originally wanted White Post to rebuild everything (Booster, Master cylinder, proportioning valve and calipers) because PMB only did calipers. At least that's what they told me. Others on this site have said that they do the proportioning valve too but maybe they don't do that anymore. White Post wanted an extra $75 per caliper to have them plated with the original finish and PMB did not charge extra for that and they cost less to rebuild. So they did my calipers and White Post is doing all the rest.
I found that it is cheaper to have your calipers rebuilt if you want the original plated finish and ATE calipers. I did not consider any other caliper other than ATEs when shopping. The booster and proportioning valve are much more expensive to purchase than a rebuild if you can find them for sale. The master valve is about the same price new as a rebuild but it was more convenient for me to just have a rebuild done with the other components.