Do I get quality inquiries from my site: Yes.

Would I pay for SEO: No.

SEO is not the only way to get traffic to your site. Most of my traffic coming to my site comes from my blog, where I write 1-2 articles per month. I try to make the posts interesting and insightful to the type of crowd that would include my potential clients (startups).

An added benefit of blogging is that your name will start to get recognized as an expert in your field (assuming your articles are good), which will play in your favor when you're talking with prospects.