If you have an "About" and "FAQ" (amongst other main pages) pages/links on your site... will that help you lower your PPC costs on keywords?
Yes, having about, privacy, contact us etc, plus a bunch of other things, will give you a better QS which will result in lower costs.
It also helps make it look like more of a website and not a one page thing. I suggest About, Contact, Privacy Policy, Terms and Conditions and Sitemap. Some people go further with an articles page, a link to a blog etc.