I've only encountered this from time to time but my experience has been that the money is terrible. The 'integrator' is more like an installer who is expected to bang out bus after bus. Not much money, very little smarts involved and a lot of hard work.
Part of the reason I saw was that these go to the lowest bidder, so the systems proposed are usually real cheap and the labor dollars committed are minimal.
I'd be happy to be proven wrong / that my experiences are the exception.
I have had the "Pleasure" of providing some quotes for systems like these - and yes they are low profit projects. My experience was soured as once I provided my bid with products requested - I find out that the manufacture quotes directly to the end user and does their own installs - low-balling every proposal I did provide.
Very upsetting - and a waste of my time and money!!
Ironically enough, I had this also happen to me. One of our vendor contacts randomly dropped in to our office once. He said he was 'in town' which was surprising since he was based in another state. Come to find out after chatting, he was in the area to support an enormous bid project that they had won in the next city over that we knew nothing about and they had gone direct on.
In my past integrator life, we won a school bus bid. There was a tech that had recently come on who used to work for the city comm center installing radios in police cars. So he could get buses done fairly quickly and there wasn't a ton of profit, but it was healthy. I think it's gotten more competitive since then. This was in the late 2000s.
I've heard of another integrator who hired a car stereo installer to do all the rough work, since those guys are more suited than typical techs. Plus they generally are low paid, so anything more lucrative they jumped at. The integrator did the config in house, installer ran cables and put up cameras, and they came out and did a final check on each bus.
I do think it's a shame that so many of these go to the lowest bidder, though. They're big projects that end up being standalone instead of part of a school or city's overall security plan.
Who are the major products players usually? Surprisingly, and not surprisingly, it doesn't seem many of the big players have a well designed solution for this.
Who were the products that ended up selling direct?
Not an expert in this space; One name I have heard regularly, though, is Safety Vision.
SEON and Angel Trax are other big ones.
There's a growing number of Chinese products coming in. Hardware is ok, software is a bit flakey and lacks a lot of advanced features that people are asking for. WiFi offload is a common request... which isn't overly hard, but the software/server back end is less than elegant from what I've seen unless you spend big dollars