Ill chime in. I just built my AR using mostly Parts from PSA, with some Magpul and a New Frontier Polymer lower thrown in. 420 rounds later with a single failure that was the fault of the weapon. Including several mag dumps. Wife tried to force a mag in backwards which caused the mag to break and double feed once I inserted it properly.
The big difference in price comes down to the barrel and accessories. Make sure you are getting a quality barrel. Typically this mean chrome lined hammer forged 5.56 chamber with a 1-7 twist but not always. Slower twist will really only work with 233 and light projectiles.
Here is a crappy cell phone pick: