Get what you can afford and that's all you'll ever need. The biggest difference from one weapon to another is the one thing no one talks about and that's the end user. So unless your shooting competition at a high level you'll be fine. I can take any AR and get a kill shot at 300 meters consistently mag after mag with iron sights. Drop on a ACOG and my grouping gets tighter and its easier to make the shot. I'll admit the more pricey ones will give you better consistency and tighter groupings with less problems but most AR's will at least get threw one combat load before you get a malfunction. Save your money on the weapon and spend it on becoming an expert with that weapon. Just IMHO