How do you calculate a fair wholesaling cut?

[Kathryn Miller Jones]

I am just starting out and feel like the wholesaling avenue is the best beginning path for me.  How do I determine a fair "fee" for the bird-dogging service I would be doing?  Is it some standard percentage based on the price of the home or a flat fee or based on profit margins?  I am also an agent so I will not have realtor costs if I have to close and then sell or if we do a simultaneous close, it is possible I could also represent the Investor (Buyer) as well.  If I do - how would that affect the amount that would be my cut?  Thank you in advance!