What is a fair finder's fee?

[Joseph F.]

I have a contractor that is wanting to partner up with me but does not have the capital to do so. The way the transaction would flow is as follows:

The contractor would identify a property for me to consider. Assuming I deem it worth pursuing, I would purchase the property. In the event that the property requires work, he would have the opportunity to work on the property. I would finance the materials and possibly some or all of the labor (at a competitive rate).

The decision what to do with the property would be mine (i.e. hold, flip, etc.).

What would be a fair finders fee to give the contractor for identifying the opportunity?