I finally found the cost of Armalite complete uppers on Wolverines website.
M15A4/A2 Carbine / Rifle Upper Assembly, 16" or 20" - $672.00
Only $7 less than the RRA, but you also have to pay extra if you want a chrome lined barrel on the RRA. So the Armalite seems to be the better deal. The dealer quotes I got put the RRA $90 more when including the chrome barrel. That includes taxes and shipping (and I have to pay PST on the RRA).
The only problem I have with the Armalite is, if you want a mid length you have to get the picatinny gas block. The RRA mid length comes with an A2 front sight. If you want an A2 front site on the Armalite, you have to get the shorter handguard.