jacko Too many options, too many variables, too many choices regarding the software that is running on the server.
It's not that much hard, it's actually fun if you get into it
if you need something easier you may be interested to centminmod
personally I don't like it because it's a little easy to work with and a little limited for me
but it can help you to manage a VPS by yourself
Dominion Toby said last July that Flarum's running on a 512MB instance. That may have changed since then.
jacko digitalocean's 512MB droplet is $5/m