Two quick points here, one for Paul and one for Nathan:
Paul is correct in his seed money calculations IF someone were to just shoot a solo girl, etc. (And I also agree most solo girls aren't worth trying a site for and those that are will probably make some nice extra income instead of "getting rich".) BUT if it's a "Ma and Pa"-type operation, or the solo girl has a lot of content she's gathered over the years, OR if she's willing to shoot content for her own site for free, then the costs are way lower. Profits still may suck tho. LOL
Nathan: THE ONLY WAY on Planet Earth to get 65 members a day, every damn day, after only a month in operation is either (and probably a combination of) MASS traffic, MASS affiliates and MASS money being invested. The average solo girl site would be ecstatic with 5 sales a day, every day, after a month of operation.
Just some perspective from my "World". LOL