This isn’t really a Discourse issue, but I’ve decided that it’s time that I have something more formal in place to know when a site is down than to happen to notice or get an email from someone.
Yes these Pingdom type services are surprisingly and shockingly expensive for what they do. Perhaps that’s a new business you could get into?
Proper monitoring from multiple locations, which is how it should be done for maximum effectiveness, is a bit more difficult than you’d expect, though.