There are several issues.
The $1200 figure likely is the flat top collapsable 16in barrel version with an EOTech included in the price and I would guess Rock River or DPMS or Bushmaster which sounds about right for department pricing but you can rest assured they are getting more than the gun. OMB Department price shows $850 for a flat top Bushmaster 16 in. I'm thiniing the difference is an EOTech.
Out of 4 agencies I have worked for two provided the firearm and the other had guidelines on what you could carry but you bough it. One of those would allow you to get a letter from the Chief and the department pay for it and take it out of your check $25 a check.
As for the current trend toward arming police with AR-15 patrol rifles I have mixed feelings and would rather see 1/3 to 1/2 of them armed with a bolt action .308 like a 20 in Savage 10FP with a scope on it - obviously the 3-9x42 Super Sniper would be ideal for that role. Chris should probably try to sell some patrol rifle packages to departments. The police designated marksman usually fires 60 to 80 yds and seldom over 120 yds so even a fixed 6x 42 Leupold VX3 heavy duplex would be ideal at that distance and much more effective with a baracaded subject or automobile than an AR-15. For some reason the novice shooter when handed a semi auto gun seems to want to shoot wildly without regard for placing the sight on the intended target. Fully two thirds of police are NOT GUN GUYS and only carry one because they have to so probably a third shouldnt even consider buying one because they wont keep up with it - those are the ones who were better off with a shotgun anyway. We have found them with their service revolvers rusted shut. I would suggest that officers who were not interested in carrying a rifle not be required to do so. Security of anything left in the car is an issue. Care cleaning and maintenance is an issue and absolutely nobody is worse about failing to clean their guns than cops. I would advise carrying the AR with the magazine loaded chamber empty.
Getting people trained and qualified to use new weapons and the cost of doing so is a huge $ issue and the availability of ammo is still not what it should be. Most agencies dont stock much ammo so after the first big gunfight in the street it's over they are out of bullets. Ive seen military units go through 6000 to 8000 rounds in the matter of a couple of hours. ( he who shoots the mostest the firstest runs the other guy off)
Selection of ammo is an issue - The 77 gr retains significantly more energy. ATK has some good dope on ammo from balistic gel testing.
I currently carry a state owned Glock 22. I've suggested the dept buy a couple of rifles or allow personal rifles, but change happens at a snail's pace unless something bad proves your point.