Feedback from a bunch of guys that bought 6.8 barrels and uppers from me.
I can get you into a basic free-floated match grade barreled upper for around $800.
Full choice in barrel length, profile, gas system, muzzle threads etc...
Fancy handguards add to the price and CDI factor, but not to the accuracy.

It really depends on what you want to do with it.
If you just want a blaster, a Model 1 or Bravo will be fine.
Last I heard, both companies are using the same ER Shaw production grade barrels.
If you want more of a precision upper, then expect to open the wallet just a little bit wider.
There is no need to spend $1600 for an upper without optics, but with a fancy "B" name on the side of it...