Okay, so just a fan / clan type site. That itself is not an overly big project.
Sounds like the UML and sequencing has yet to be done, and the database is not complete, so no functionality currently exists. This would indicate that a single PHP developer will be acquiring between 75% - 90% of the overall workload on the completed site, yet the standing offer is a 15% of potential profits.
Thanks, I think I'll take a pass.