i think that if i was buying an AR now, i would look at the top shelf guns as a "might as well"
in other words, if you are going to spend $800 on a cheap gun, you might as well spend $1000 or more on a GREAT gun.
if i ever buy another AR, i will be one of the high end brands, because i keep my guns forever (at parents farm) and want them to run forever.
if you gonna swap parts & customize, then yeah, go cheap and end up with good parts in a cheap housing.
but there's no real value there, and your money is only good if you keep the gun forever.
mix &match & homemade guns don't hold their value.
but for me, i know what i want, and will save up till i can buy a gun LIKE i want, that is all one brand, one color, one finish, and with a warranty.