so i'm in the process of building my first AR...looking into the upper parts category. as of now, at the current stage of my life, i don't make it to the range as much as i want to. i also lack the funds to shoot thousands of rounds each time i go out. so for now, the probability of me shooting out a barrel, or wearing out a bcg...so in your opinions, what are the benefits of a $200 bolt carrier group vs a $100 or less bcg?

as far as the barrel goes, i'm finding it "cheaper" to buy an assembled upper from aero than it is to buy all the parts separate and assembling them myself (which is sad, because i really enjoyed assembling the lower and want to do an upper now) am i sacrificing quality and accuracy for going a cheaper route?