Once your domain is setup its available for use with Projects.
Domains and Subdomains can be assigned and reassigned in the interface and no further management is required.
If you change a server or cloud host, the domain is automatically reassigned to the new server.
You can create as many subdomains as you want. Subdomains can be assigned to different projects.
We don't add any markup to the cost of a domain.
If you are concerned about cost then you can always just buy your domains elsewhere and:
If you want to take your domains with you we can transfer them to you. Just create your own account at DNSimple and contact us on support with the details so we can arrange the transfer.