Additionally you would want to rank the repair facilities. During my time in the Army, I saw quite a few motorpools and based on date built & for who, they could vary in the level of equipment & service.
FREX, one had a environmental storage- basically the big shed was climate controlled to protect the equipment from temp extremes as well as corrosion. Same place also had a electronics shop set up inside to work on the computers in vehicles rather then sending anything off to another shop on base. The bays also had recessed lifts . . . while that did nothing for the armored vehicles, it did let them lift up the Humvees to get tires changed or other service underneath. I think that place also had power & compressed air on pivoting arms from the ceiling.
Then another one we were in was from the 50s or 60s, had the bays for vehicles to drive through but that was it. And the bays were smaller then the more recent builds and had none of the efficiency improvements of more modern construction. Not to mention some doors had been sealed off to make areas more secure storage or when rooms were repurposed over the decades. Drains might be clogged or channels filled with dirt & debris so spills were not routed to drains properly. Barely ventilated to remove the fumes from substances, welding, cutting, or painting.
Finally you had facilities that were barely there . . . yeah a building with the bays in to give shelter from the elements, but you were parking that truck the techs used in the field as close as possible b/c that is where all your tools and supplies were coming from. Rather than a concrete pad, it was a dirt/gravel floor of the facility. No doors on the bays, no ability to drive through the bay.
Sounds like the in-universe facilities would have different rating codes for what was provided.
Something like:
A - you have a roof over your Mech's head and your head, the admin/medical/cafeteria building is another empty building with particle board separators between the cubicles (unless someone knocked them over domino-style), and the perimeter is just some chain link fence . For everything else, buy or bring it yourself. Advantage: cheap, and the owner might not care if you break the place (the fee for using it likely assumes the whole place has to be torn down and rebuilt between clients). A water tanker is contracted to come in once every couple days and fill up the cisterns underneath the main building while sewage trucks take away the smelly stuff. The only way this base could be worse is if a storm came by and knocked down the buildings. Also, don't have the infantry do jumping jacks on top of the septic tank, the cracks are a bit worrying.
all the way to:
G - ARTS based repair systems allow minor damages to be repaired automatically plus rearming if needed, 600-ton sized Mech Bays gives a +1 to all repair rolls to fixing your Mechs (normal Mech bay is 50 tons + 100 tons for the Mech, this is 500 tons + 100 tons for the Mech), and dedicated Mech simulator networks allowing your entire force to train in near-realistic environments. The Infantry barracks are comfortable and custom-built to the unit's requirements and requests.
(I go with 'A' as the lowest possible as it allows for extending capabilities with more letters. Otherwise if you have an A-C category with 'A' being the best, you might later have two additional grades of quality, and 'C' rated facilities that were once worst of the worst are now considered average. In-universe this would be locations overcharging for what they actually deliver.)
Each letter code would indicate what items are considered minimums for that level of quality. So you could have a base that had D level Mech facilities, E-level communications capabilities, C-level vehicle support, but only B-level admin center/cafeteria facilities. That base would be rated as 'B' since that was the lowest level of support.
So the cost chart might list the different facilities as:
Lance-F = best equipment ever for repairing your Mechs, direct access to the local trauma center in case it is needed, but it can only handle a very small unit that has a very big bank account
Regiment-A = the place can fit your entire unit easily, your troops are dry, your Mechs are covered, but your security needs are higher than your last anti-guerrilla contract because the place is in a valley between two hills, and those hills are not part of the property so you are not allowed to deploy troops up there. Also, don't drink the local water. The only nice part is that if your troops punch holes in the walls nobody will care.
