feditips@social.growyourown.services thenexusofprivacy@infosec.exchange I think their estimates are on the conservative side.
It's true that a single user instance can be hosted cheaply but regular things you do to fix federation issues will drive up costs.
For example, when I hosted with them I used a relay so that my content reach would expand. That drove up my disk usage costs to the tune of $20+ a month.
