What's the difference in performance?
For that matter, what's the difference in performance between a budget AR and a premium AR?
Nothing for the first few thousand rounds.
What it comes to is whats the life of the rifle going to be like. If you want something thats going to be in the safe mostly, running a couple hundred rounds through it a year then get something lower end. Del-Ton, PSA, DPMS. If you're going to run competitions, do schools with it where you're getting it dirty and running a lot of rounds through it in short periods of time you're going to want a higher end rifle. Something that has been built to mil-spec. Theres processes like proper staking of gas key, shot peened bolt, chrome lining, etc that goes into the build of the middle and top tier ARs that you don't get at the price point of the lower tier. Not all low tiers are equal so do your research.