Put a pump on a trailer. The problem with this country is we're not allowed to have "decent"; we are only allowed to buy the "best" and so we just hobble along with old shit while everything's breaking down and we're paying too much for the things we do buy.
In Australia that's either an ultralight tanker, which would cost around $100k USD today but with far lower 550L capacity and a lower throughput pump than a heavy tanker, or it's a command vehicle, and its modern equivalent would cost about $60k USD but have no pump or water tank. The ultralight tankers are mostly used for getting to fires faster when they're small, dealing with inaccessible terrain, or just being an extra vehicle during blacking out etc.
The problem you're always going to run into is that your truck needs to haul around 10 tonnes of water and protect its crew. You can stick a pump on the back of a hardened ute, but then you need to leave and find water 20x more frequently plus your pump is a dinky little water pistol, or you can drive a commercial water tanker into a bushfire, but then your driver needs to be unusually brave and no longer have much to live for.
I accept that firefighters are getting ripped off, but it feels like maybe 5% to 20% of the cost could be reduced, and then you're still dealing with unaffordable equipment.
Most fire engines in the US don't carry significant water, they're "pumper trucks" for boosting pressure from fire hydrants. 80% of US citizens live in urban areas with access to hydrants. They also carry lots of other gear too: https://rosenbaueramerica.com/fire-trucks/pumpers/
But you can do everything those do with an E-series cutaway ($200k fully outfitted?) and a pump pulled on a trailer. For a whole lot less than $2M.
Here in rural Western Australia there's a range of official vehicles, the local (wheatbelt area) farmers have supplemented them recently with an ex military unimog purchased at auction and fitted with an 8 (ish) tonne water tank (with anti slosh baffles) and extra cab insulation.
Not sure where specifically they sourced it, one of the military surplus auction houses like:
Put a pump on a trailer. The problem with this country is we're not allowed to have "decent"; we are only allowed to buy the "best" and so we just hobble along with old shit while everything's breaking down and we're paying too much for the things we do buy.