I was looking for kahr custom shop prices and stumbled on this information from kahr website.Not sure if there is a thread on this or not.I couldn't find one so here it is.

Upgrade Services
For any questions or to request any of these services please contact Kahr Customer Service at 508-795-3919.
Sight Installation Service
Installation of sights performed by a factory technician.
$40.00 plus the cost of sights. + S&H ($25.00)
K9 Elite Trigger Upgrade
The Elite trigger upgrade for the K9 pistol includes the installation of an Elite trigger system performed by a factory technician. The Elite trigger shortens trigger pull. The Elite trigger system includes a highly polished trigger. Firearm will be tested for functionality. All parts are included in price. Not available in some states and cities.
$125.00 (includes cost of parts) + S&H ($25.00)
Polish Package
The polish package is a full polish of feed ramps, slide stop lever, and barrel hood. The polish package improves the comfort and cosmetics of your Kahr pistol.
$65.00 + S&H ($25.00)
Polish Package Deluxe
Contains all attributes of Polish Package but includes polishing of stainless steel slides.
$130.00 + S&H ($25.00)
Refinish Package
The refinish package removes imperfections that may appear on the finish of the Kahr pistol over time. Glass beading all metal components (e.g. slide, frame) to remove light scratches and discoloration.
$160.00 + S&H ($25.00)
Black Oxide Refinish
Re-coating steel parts that originally had a black oxide finish.
Tommy gun receiver assembly (lower, upper, barrel) $150.00 + S&H ($25.00)
MK series Slide $75.00 + S&H ($25.00)
K series & Auto-Ordnance 1911ís frame & slide $125.00 + S&H ($25.00)
Factory Tune-up Service Package
The factory service package is an overhaul and tune-up of your Kahr pistol. This includes a complete cleaning and inspection of the pistol. All worn parts will be replaced. At a minimum the following parts will be replaced, recoil spring guide assembly, striker spring, trigger bar spring, and slide stop spring. We also polish the feed ramp and replace the extractor for smoother operation. Firearm will be tested for functionality. All parts are included in price.
Parts to be replaced include:Recoil SpringExtractorGuide Rod AssyTrigger bar springStriker SpringSlide Stop SpringTotal package price is $175.00 + S&H ($25.00)
Update Service (P & PM series firearms)
Bring your older Kahr pistol up to date. This update service modifies older revision frames to accept new revision barrel & recoil assembly. This modification also allows you to use ported barrels in your Kahr pistol. New revision barrel and recoil spring & guide rod assembly included in price
$190.00 + S&H ($25.00)
Note: Services are only for firearms made by Kahr Arms and Auto Ordnance (Worcester, MA). Other non-warranty service will be billed at $65/hour + cost of parts + $25 S&H. There is a minimum $65 charge