I think it was pointless that Anne Arundel County wasted all that money to pay for this. I can see that Maryland State Police but not Anne Arundel County.
If I remember correctly, it was mostly grant funded through a combination of state and federal grants. They didn't just decide to go out and spend the money on something; the vehicle was acquired as a result of communication and command failures in previous disasters.
They also found out through experience that only one of these per X counties in this region wasn't enough as it usually is elsewhere; the city has a similar vehicle, MSP does now, and so does Montgomery (and maybe PG) but they aren't going to share if we have a regional disaster.
AA County has a population of over 510,000 spread out over 588 square miles, with 534 miles of shoreline to tend, compared to actual Baltimore city limits and population, which is only 92 square miles and 627,000 people. It takes lots of resources to protect that many lives and that much property, especially when it's as diverse as what we have here. Also bear in mind that we have the state capitol, the largest airport for ~40 miles, and the entirety of Ft. Meade within our boundaries. Also, with the BRAC bringing another ~100,000 people over the next ten years to the county, the county must be able to provide safety to all of us.