Honestly, you'll be hard pressed to find all the wheelbuilding components for cheaper than a standard wheelset from velomine. Additionally, wheelbuilding isn't just putting parts together and calling it good, it's definitely a skill. I'd hate to discourage you from DIY, it's just not really practical for most normal riders with a mid-end budget.

I'd definitely want to ride the S2C before buying a wheelset with it. It's a rather heavy wheel, the cog isn't standard threading(as far as I can tell) and thus isn't easily replacable, and lastly, it adds a level of complication that may not really be necessary for you. Just something to think about.

That being said, if you do decide you want to build your own wheels, the book "The Art of Wheelbuilding" seems to be the go-to book.