I have spent only for the domain name and tried a PPC for $25, that was all my “physical” costs.
But… as my profession is online marketing and development I have built the site, manage it, look for quality links, write the content, read poker books to understand more the industry..etc.. so I devote a lot of time to it (and my time is very expensive for my clients, so if I take my hourly rate, I would end up with a nice sum to charge to myself.. 
)
I think the way to go is SEO and to form a quality site where visitors want to come back.