I think you are asking something most of us do, more money= better quality, and it's logical. If a receiver is "mil spec", than it's held to certain tolerances. Just remember that there are allowable variances within the tolerance range. I have one each of the following: DPMS, Stag, Cavalry Arms and Essential Arms. The Stag, Cav Arms and DPMS were roughly the same price. I bought the Essential about 4 years ago for $65 new. I don't even know if they're still in business. They used to sell factory direct but stopped shortly after I bought mine. They all accept mil spec parts perfectly and all function perfectly. The Stag and DPMS are very well finished. The Essential shows marks as I think they are (were) cast. I haven't notived any better FUNCTIONAL quality by paying more, but I am sure others can offer bad experiences in buying cheap.
"People live too long, dogs don't live long enough" - FTF Member-