True Art,
But it is easy nowadays to buld these rifles in the $400-$500 range with all NEW parts. The disign is simple and does not require the expensive barrel headspacing tools that are required with conventional rifles.
Most parts are built to drop-in, and the average hobbiest has the punches and hammers required. The only 'special' tool is a barrel wrench that sells for $34.
There are hundreds of people that use the 'BUILD IT YOURSELF' forum at
www.ar15.com for support and nearly always end up with a new rifle in the end that funtions perfectly.
Of my 5 1/2 ARs, only two of them were factory built, and there is an endless supply of manufacturers and parts to choose from.