Yep, but apples to apples, it's about the same cost. A full time officer compared to an active duty soldier. Excluding variables such as off post, base housing, etc. Assume E-1 to rookie officer. E-1 lives in the barracks, Rookie officer has roommates.
A rookie officer starts at $57k, gets a take home car, and a set schedule and overtime. The E4 gets $42k, no over time, no take home car, and a constantly changing schedule and has to have permission to live off post or take time off. Military is cheaper than any cop.