Well.the first thing Google Offers Pay Per Click (ppc) Services through Adwords Program and not CPC or cost per click.
And PPC and SEO bith have their own advantages and disadantages.
In PPC you get instant resuts and as soon you stop paying your ad will stop showing and SEO is long term process require patience as it results in long time.
Read here in detail at -
Pros & Cons of SEO and PPC