M+P's, DPMS, Rock River, Stag, and others, are all hovering around $1000 or less for the standard models, the bells and whistles can be done as you become even more familiar with an AR platform. In essence, the receivers are about the same.
Be sure, it is the caliber and rifle for what you want it to do. Think of mags, ammo, barrel length, features, ease of use, field stripping, spare parts, etc,..
Take as much time as it takes to test drive, research, study, ask around your local shooting places, and get a feel for what it is for YOU.
There is great resources and knowledge here. $1000.00 is a good price to get a great AR rifle. Welcome to DRTV, post any questions or ideas your kicking around, you will get a straight and honest response regarding brand, triggers, options, future upgrades, etc.
Glad your here at DRTV.