Metalworks is a open-source platform to host your FoundryVTT server on DigitalOcean. You pay for what you use, nothing more. Guaranteed to cost less than 6 USD / mo, and often as low as 1/2$ a month.
Go to https://dnd.tenzin.live and create an account. You will be prompted to create or join a server. Since you're creating one, you'll click create.
You'll need to provide a DigitalOcean API Token, and a name to use for the server subdomain. After that, click start, and in 10 or so minutes you'll be all set!