Yep. I saved hundreds or even thousands of dollars a month just from switching from Substack to self-hosted Ghost.
I pay a roughly flat $85/month now (~$75 for mailsending, $10 for hosting), vs. 10% of all my subscription income.
Here’s some napkin math for how expensive Substack is compared to its competitors, assuming that roughly 7% of all subscribers will pay for their subscriptions, and that subscriptions cost $5/month.