You have to watch CTD, sometimes they're not as cheap as they say, but overall they're ok. I expect you'll get (at your FFL) what you ordered and at that price.
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