Yes, it's a bit of a time investment but as your business grows with your CMS expertise, it'll be worth it.
I look at development with a CMS as basically a three pronged approach:
1) CMS setup and configuration. Getting the basics up and running, installing the appropriate modules and figuring out whether it's basic static type content or image galleries, news sections, events, blogs etc... Knock out a bunch of blank pages if you're still waiting for content and get the navigation fleshed out. Sometimes there's some custom code writing in this stage, sometimes not.
2) Theming. Applying the design to your CMS. Often times I'll have to write custom code in this stage so it's good to know the CMS API well here.
3) Customizing and fine tuning. Once you have the design applied and hopefully the content has arrived. Now you get to see how it really looks and you'll have to fine tune it so that everything works in concert.
It's more involved than that but that's the gist of it.