I have one domain with two email addresses…hosted at MS Office 365…and that ends up costing me nearly $125 per year. It can't be avoided due to user requirements.
Another domain I have has a cheap website host. This totals around $30 per year. The website host provides its own IMAP email with limited space…so I use it but I move all the emails to a Gmail account so that I don't exceed the storage limits. An added bonus is being able to do this with multiple email addresses @thedomain.com.
Whether or not such a setup will work for a user depends on the user's requirements, I suppose.