As others have said, not a problem starting with a base gun and then modifying as money starts showing. After optics and mounts for optics I'd be looking after an upgraded trigger and then bolt carrier group like a nickel/boron.

Mine started as a 600.00 gun and ended up about 1700 after modifying but that did not happen overnight. Only thing left is the DPMS lower and a couple other parts. But the other DPMS parts went to other guns that I'm very happy with.