I recently bought a Kahr CW9 after comparing it to the similarly-sized P9. The CW9 is an excellent pistol at a great price, I bought mine for $379. The CW9 (and the P9) fits my hand and balances much better than the PM9 I've owned for a couple of years, it's not much heavier, carries one more round and is just as slim and concealable as the PM9. The CW9"s slightly deeper grip and longer barrel handle 9mm recoil very well and it's a real pleasure to shoot during extended range sessions; the PM9 tires me more quickly. Both the PM9 and CW9 have been totally reliable, even during the initial break-in periods, and they are great pistols for CC. But, that's not the point of this posting.
The primary differences usually cited between the less expensive, "economy" CW pistols and the costlier, higher-end P guns are the more finely-finished slide, the quality and accuracy of the Walther barrel rifling and the machined-vs-MIM slide release/take down lever. All the other components, including the polymer frame assembly and magazines, are reportedly the same.
However, the prices for these three replacement parts (slide, barrel and slide-release/take-down lever) shown at the Kahr Arms website for both the CW and P series are exactly the same. The only part that costs more for the P series is the SS guide rod, it's about 7X more than the plain, blued carbon steel rod found in the CW pistols.
From everything I've read, these parts are interchangeable. But, even if they're not, the prices of the more expensive P series pistols are primarily justified by the "higher quality" parts not used in the CW series. So, what's going on here? Shouldn't these replacement parts for the P series cost more than the same ones for the CW?