How Much Should I pay for a 4 course, 4-5 star Chef for 40 meals a night, 2x a week

I would like to hire a creative chef or executive sous chef to prepare 40, 4-5 star, meals 2x a week using fresh ingredients and cooking outside on a professional outdoor grill and burner set up on the island of Oahu, Hawaii.  .  We provide the servers.

I will pay all food/material costs. The job will be ongoing and 2x weekly. I need a creative executive chef with very good(at a minimum) skills.  They would be responsible for planing, prepping, and executing the presentation.  

Would I be $10 a night per guest($400)? would it be $20 a night per guest($800)?  Would it be $30 a night per guest($1200)?  

Looking for opinions.

thanks