Great price, and the 6920 is a great gun. Nothing illegal about the LE only markings in a free state like TN. Of course make sure there are no local restrictions. I mainly say that since you say you're from Clinton!
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together. You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek