A VPS is far more valuable than an email account. Compared to an email account, there are a lot more things you can do with a box in the internet you have root

A VPS is far more valuable than an email account. Compared to an email account, there are a lot more things you can do with a box in the internet you have root access to. That value difference is more than $10/year. There are reasons to pay an email provider $50/year, but I don't think being $10 cheaper than a VPS is one of them. You have to provide something beyond what one can get with a VPS.