I'm in the same boat, but since ~2006 when I started my first company (dont recall exactly when I set up my google apps account though). I have to chose whether to move my account (which thanks to sign in with google is attached to more places than I can even remember), or pony up $6/mo/user with 20 friends and family having email accounts under my domain.
I have not yet decided what to do. But if I leave Google. I will leave for life, and that includes multiple other Workplace accounts that I already DO pay for. I'm sure losing a few thousand a year doesn't matter to them, but mail-in-a-box seems like a decent fit for my limited email I actually use on those older accounts.