I don't understand some of the complaints about the ACR that I have read in the past few days, specifically that the ACR [now] has no desirable features. I honestly do not understand that comment coming from anyone who has an interest in fighting/practical carbines. Using the AR-15 as a baseline, it's trivial to list improvement features on the ACR.
That is not to say the ACR is perfect or it's a great price. But let's put the cost in perspective. Your average entry-level AR-15 is around $800. Add a UBR stock: +$250, add sling swivel hardware $80, add BUIS $100 (minumum), add MIAD/TG $50, add ambi controls $80, add float tube / top rail system $200. Just considering those changes you're at about $1500. Gas-piston AR-15 uppers start at about $1100 and go up from there, figure a price differential of $600 over a DGI upper, so that's +$600. Something with an uninterrupted top rail like the LMT MRP is about $1100 again, so there is a price differential there as well. I think if you look at it this way, the ACR's price is not way off.
However, I would have liked to see it come in around $1600-1900 retail.