It doesn't take that much more. Office 365's base plan is something like 35£/year, plus around 10£/year for a domain. They offer IMAP import so migrating from Gmail is seamless.
After cloning the repository and installing the listed dependencies (some Perl packages available in your Brew / Ubuntu repository already), you can do:
I've used imapsync in the past to migrate thousands of mail accounts from and old decrepit IMAP environment (with some weird edge cases) to a shiny new IMAP based mail platform.
It's a hugely flexible and versatile tool and it's quite zippy as well, can highly recommend.
Effort, not money. As a Firefox/gmail user who routinely shits on Google, it's mostly the lock-in of any email address that keeps me coming back. I've actually opened a few paid accounts, but effort to switch is real. I gave up partly through switching over the dozens (100s?) of services that send me emails. I would never get to the point where all of my acquaintances and relatives actually use the new address.
This is precisely what I have done and it's worked great. All services I use (and care about) I've changed to use service specific aliases now and it works fantastically well. Effort wise I'd say I spent probably a couple of days migrating some ten odd years of email from gmail, setting up domains etc. All in all, the migration itself was done within a week. Only maintenance I do on this setup now is send receipts to my accountant, and update credit card details when needed.
https://github.com/imapsync/imapsync
After cloning the repository and installing the listed dependencies (some Perl packages available in your Brew / Ubuntu repository already), you can do:
Works great for importing to and from Gmail, but you might want to add a folder rewrite for the Sent folder (with --f1f2).But with FastMail, for those interested, the out of the box importing tools in their web interface work great, so no need for any command line tools.