What is Fair Project Mgmt Fee on Rehab

[Toan Hoang]

What is a fair PM fee to manage project. Includes all coordination with subs, all material purchases, and timely completion of job. I am the investor but want to know what is reasonable for the PM. This is only project management work. Not any labor on the rehab. But i understand that this is a job in itself so i want to be fair. Does anyone have this arrangement? If so any ideas on structure?