This is for a service which is basically identically (except in some ways where it is less functional) to their free offering but linked to a custom domain, and a service they told us they were planning for to be free forever.
I wouldn't mind paying something, but this charging per accounts is ridiculous for something that was free.
I would have used the service differently if I thought it was going to transition to a paid-for service.
For example, I have an elderly friend who I hooked up to the Google ecosystem using my domain because I thought it would be slightly easier to troubleshoot any issues he had if he had problems. He wasn't costing Google any more than if he had an @gmail account. (Presumably he brought in the same amount of money, rather: if he was profitable under a free account, then I imagine he was just as valuable on an Apps account).
He doesn't even use email, so the custom domain doesn't really help him. He will be just as happy to use a free @gmail account, but I will have to spend an afternoon some time in the next few months driving out to see him and updating his accounts and devices. And then doing the same the next weekend when I've missed something. And then doing the same for some other users.
I feel like I would comfortably fit into any sane "free tier" they wanted to offer with some restrictions and low volume limits.
I have been planning to move more and more of my personal email over to my personal domain (currently mostly all running on my @gmail.com address), and eventually would have been happy to pay for the privilege once I started consuming more and more resources.
I'll see how I feel in 6 months if I've bothered to migrate over, but I might as well now look at alternative options.