KimPro - from the 1999 catalog - "...the hardest thermally cured firearms finish available...a phenolic resin...resistant to acids, oils, saltwater and solvents...contains molybdenum disulfide...self lubricating...nominal thickness...Custom Shop can refinish in a matter of days."
The stuff does wear off on the sharp edges from holster wear and such.
Prices...I have no idea on a used one...I bought a Stainless Gold Match locally in late 1999 for $1049. According to the notes I made in the catalog, the Gold Combat was $1250 and the Stainless Gold Combat was $1300+ (with an MSRP of $1480.) The nights sights were standard according to the catalog.
The only problem I've had with my GM has been a broken rear sight (after a couple of years) and Kimber sent me a new one for free. I really only needed the nut for windage adjustment screw and thought that was what they were sending. Boy was I surprised. I admit I've replaced the MSH, bbl. bushing, extractor, slide stop and such, but only because I had too much money and was in a tinkering mood. And I just bought some Spegel grips for it that I really didn't need. 10,000 rounds, more or less without looking at my records, and counting.
John