A lot of users on these are opening up public instances, rather than their own. I don't see a huge amount of "host mastodon for yourself on your own domain" people.

I went this route (via https://marketplace.digitalocean.com/apps/mastodon - I would have used masto.host otherwise). Im keeping an eye on Takahe (https://news.ycombinator.com/item?id=33731739) as hosting mastodon is kind of expensive, for the type of use I make of it.