I doubt one would save any money by building this one - although I understand some would still prefer to. Let's hope it isn't like the MG34's. An 80 percent receiver goes for under Five but the semi conversion sells for $1900. That one I'll build myself since there is a huge difference in price - and I like doing the "off" builds.
As far as the Vectors not being "correct".....no matter what you build, it will never be correct as long as it's a Semi. So, if it's off somewhat, no biggie to me. Same with the AK's we all build. Some take off Bulgarian parts and replace them with Russian just to get a casting number. It's still a US made incorrect receiver. But, whatever chokes your chicken - isn't this a great hobby :)
Personally, I really like my Vector RPD.