It really depends on what you are trying to accomplish...
Most of my new clients are trying to shoot their own exclusive content. From a legal standpoint as well as being noobs I tell them to hire or contract for content from an experienced shooter in LA. There are plenty available at a reasonable price and this is where all the talent is. As a new site you will want to use established names in the industry to drive traffic through search engines.
I would also recommend launching with no less than 50 scenes ($1,000 to $2,000 per) spread across at least 3 niche sites. Do NOT try to compete with the big boys and pay for sign ups or rev share at first. Hold off on the affiliate program until you have cash flow. Start a couple of blogs to help drive potential members, buy some traffic as well.
As for pricing, the lower the better - $9.95 to no more than $14.95. With a scant 50 scenes you cant charge $29.99 since you dont have the content. Also you want rebills to build cash flow. You can raise prices later.
I tell my new clients to start with no less than $75,000 and much better is $125,000. Dont expect positive cash flow for a year and dump all your money back into content production as fast as you make it.
It aint easy money anymore, but it can be done.
Oh yeah, get a solid lawyer and accountant first. That will save you some cash in the long run.
Good-luck.
Michael
http://www.adultbizlaw.com