SEO is not to be underestimated! Its one of the BEST things that you can do for your web presence. Either build your website and spend money on something that improves over time or throw your money away at a web presence that does nothing over time ie PPC.
Use webgrader. It is free and will tell you what you need to do to make your website more search engine freindly. http://websitegrader.com/
The longer you have your website the better it will rank. Keep your content updated frequently and do what webgrader says and this will be a good start to SEO until you can afford to pay for some PPC and SEO
Some SEO people can actually hurt you more than help you using tricks like link farms, etc. Google's Ad Sense algorithms are pretty good about working like the real world should, rewarding popular sites that have been around for a long time.
I recommend participating in online forums, and linking to your site in your signature... that can help a lot as GoogleBot finds and travels your signature to your site.