They aren't doing fair business. Either they have customers or funding lined up, or you take an even split. A guy who gets paid $7000 to build the site is not

They aren't doing fair business. Either they have customers or funding lined up, or you take an even split. A guy who gets paid $7000 to build the site is not the guy that keeps the servers running, is not the guy that backs up the database, is not the guy who organizes further engineering efforts should the site take off.