^this. As long as it's been taken care of, a used rifle will perform just as well as a new one will. Might be worthwhile to look in the classifieds for awhile before buying new. Someone may already have what you're looking for!
Still being new the AR rifle (just got my first 1 last month), I found better luck getting a used ANIB. I also didn't have to sort through all the upgrades, before I had any idea what I extras I wanted.