depends on the training ammunition for cost.
Sim rounds for small arms are actually more expensive then live rounds, as in Chalk or paint rounds for rifles, and machine guns. (honestly I thought the sims where better then the miles gear, sims made sure you got a healthy interest in find hard cover) SRTA rounds cost about the same.
When I was a Brad gunner, our training ammo was straight steel rounds, which cost about 8 bucks a shot (Guessing) , compared to the Fused HE, HEI, AP, or API rounds our bushmasters used in combat. We also fired off "out dated ammo"
The training missiles where a Laser adapter inserted into TOW tubes, I think one cost something like 50 grand. We only go to live fire tows about 3 times a year. But we had SIM gunnery every couple weeks.
Oddly enough Tank rounds to simulate HE uses a small powder charge, with a burster to throw dust around. While the training sabot rounds where basically steel lawn darts, and not High velocity Tungsten tipped DU rounds.
Force one force training rounds for tanks is a Laser adapter inserted some way into the tank gun, so it would emit, but your loaded still had to put a low powder round into the tank breach. As I understand it, not a tank cranker.
I can see Mech units using the same types of set up. Or Given laser assisted targeting, might not need most of the adapters, maybe the equivalent of blank charges to make some flash and noise, while the lasers, and computers score every thing.
Initiation to War, has some pretty descriptive "semi live" mech training in it.