M&P Sport - $600
RRA match trigger $85
$685 with a 2 stage trigger and a lifetime warranty. Hard to beat.
Unless you want to build. But don't do that until you've owned a couple and know how you want them configured. I like upgraded triggers, adjustable gas blocks, ambi selectors, ambi mag releases, stainless barrels with threads for compensators and cans.
If I buy a production gun, I end up spending $300 on customization that adds little to the value of the gun. If I build, I'm not paying to change stuff out.