Thanks Charlie! Posthaven cofounder here. In the short term we will run your blog go $5 a month. We've taken a pledge not to get acquired and to run it for as long as possible. Right now we are building it out but in the future as we grow we would like to make a foundation that will fund it in perpetuity out of the profits. The site is profitable and self sustaining now. Definitely a work in progress but a blog that lives forever is our goal.
Permanent URLs are a powerful idea, and it's a feature of using Posthaven we think you should get even if you stop paying. We'll keep the site online, but you won't be able to edit content or add to it. If you want to renew, start paying again and your account will be restored.
When will something qualify for permanent storage? Let's keep it simple initially: If you pay for a year's worth of service, your content is safe and we'll keep it online.