After tons of research on the way ahead for the Squad Designated Marksman Rifle (SDM-R) and looking hard at what I am wanting, I decided to build an AR for Service Rifle matches. I have the upper and lower receiver, but I will basically need to start from there. I believe I can do this for under $500 if I am smart and look for bargains.
Free Float sleeve~$75
That leaves about $25 for incidentals.