How to compensate broker that is managing my rehab.

[Sharon Anschultz]

I am working with a fella that I contacted to just get an idea of the market in the area before I purchased a property at an online auction.  I am already going to pay him a 3% commission for the purchase as he has been inspecting the property multiple times and giving me regular updates on the market and pointers on how to negotiate with the seller (bank), but he is also assisting me with getting bids for the rehab.  He is being my boots on the ground.

When I sell the property (leaning towards a fix and flip), it seems that the commission is not enough compensation.  If he gets the full comission, it might be fine but 3% on an $80K home, is that adequate for managing the rehab and selling the property?  As there a contract the a specific contract that I should use with him for this work?