If a website doesn't have that much search volume for their primary keywords, is it worth spending money towards SEO if very few people will be searching these keywords to begin with?
Many people have the misconception that SEO means ranking keywords on Google. That's not the right concept. SEO means Search Engine Optimization. It about optimizing your website for search engines. Ranking keywords is just 1% of the overall game.
I think you should focus on branding and inbound marketing rather than on SEO or PPC alone.
I wrote about it in my book, "NO SEO FOREVER".
If you want to talk more about it, I am always here to help you out.