Someone correct me if I'm wrong, but I don't think the biggest threat to domestic military facilities are foreign state actors but rather domestic terrorists, and those usually don't have access to any military-grade satellites.
Interesting that you mention only domestic military facilities... When I was deployed to Afghanistan ten years ago, with rockets and mortar rounds landing daily inside the perimeter of our Forward Operating Base, I was irritated to see recent and high-resolution satellite imagery on Google Maps. I can see my sleeping tent, office building(s), and parked helicopters in perfect clarity. The imagery hasn't been updated since then, so you can still see everything despite this base being abandoned years ago.
https://www.google.com/maps/@33.9428134,69.0629605,492m/data...
Do they need military-grade imagery? The Chinese or Russian militaries do because they’re trying to estimate war-time performance but I find it hard to believe that there are any domestic terrorists building sensor arrays to support SAM batteries. If they’re trying to blow one up, the resolution on a consumer drone or telescope would likely be more than enough.
For my family's semi-rural home I'm seeing that I can buy 0.5m (500cm) imagery from the last year for $250. No historical images with higher resolution I can buy. To task a new a photo at 40cm resolution would cost $1,800.00 from KOMPSAT-3A. (and it'd be a 10km x 10km area)
Not all of them. Some of them just don’t offer photos of that area, even though they offer literally every other inch of the earth in at least SOME scan, a lot of these are missing.