For my newest site, startup cost was pretty minimal. Most was paying the $750 VISA registration fee through ccBill. I have probably put a few hundred into it so far in scripts. I really only have to make a couple of sales to cover my entire years hosting. Needless to say I am making a profit and have paid off all my expenses.
The only thing that can't really be calculated is the number of hours every day I spend working on it. In that case, I have about 1 million dollars invested into the site, and I'll never see a profit!
