I would charge far more for a mainstream 'application' than an adult web site, simply because adult basically has a consistent, pre-defined, statement of work, or functional spec. Whereas, mainstream applications require a lot of time producing the necessary documents to prevent feature-creep. It also takes far more time developing sever-side data management since each application is mostly unique. A non-application mainstream web site would be roughly the same as an adult oriented site in time and money.
