KAC and JP rifles ARE among top tier rifles, no doubt about it.
Questions: Why are V Seven complete rifles expensive? Why are their parts expensive?
The light weight is one important reason. Going lightweight and retaining necessary strength, precision, and durability requires diligent engineering, pricey machining, more expensive materials, and costly finishing.
[RANT ON] Personally, I think light weight is typically and has always been seriously under-valued in weaponry. Why should a rifle you're going to potentially have to hump 99% of the time more than you actually shoot it be heavier than it really needs to be? There may not be an apparent return on investment getting a rifle weight down X-ounces if it costs Y-dollars more, but what about the return on investment to the overall mission success? [/RANT OFF]
There's more to V Seven rifles and rifle components than just light weight: There's the fact that almost every single component in the weapon, from the push pins to the muzzle device, is re-engineered and crafted by V Seven in house to the highest industry standards, with a keen eye toward minimizing weight wherever possible.
They've gone and re-engineered and then custom built nearly every part of the rifle. Would it not have been more "cost-efficient" to buy, like most big outfits do, every non-branded component from "ACME AR-15 Parts", with only upper, lower, receiver, and barrel really made in house?
Quite clearly, V Seven chose to go another way.
Example: On a (your favorite brand here) high quality rifle, the receiver push pins appear to be generic parts like you might find in any random parts kit. That's never the case with V Seven components. Are these push pins sufficient? Sure. Can anyone scientifically prove that a V Seven push pin made of stainless steel (DHD), aluminum (V7 - 64% lighter than mil-spec), or titanium (V7 - 45% lighter than mil-spec), and then Ionbond DLC coated is measurable better than a mass produced generic yet top quality high carbon steel push pin in an era of CNC machines that can hold ridiculously small tolerances? My guess is no. Does the V7 push pin look WAY better? Oh, hell yeah.
Now, add up all the parts in an AR' and apply this same philosophy to each. You get a light and efficient rifle that just happens to be drop-dead gorgeous. And, in the process, pricey. You get to decide if the return on investment is there for you.
My strong intuition is that a small but efficient and highly experienced outfit that engineers and then builds almost every component of a rifle is going to apply all of their available resources to do their dead level best to build every component part of the rifle to the highest possible standards. That's V Seven's way of doing business. Start saving.
As a long time custom AR' builder, I truly enjoy doing what I do. Using top shelf parts like V Seven's is a real pleasure. I don't have to "make" things work. They just do.