Why would a builder want to partner with me?

[Derek Lamonde]

Initially I contacted a builder to inquire about putting a MFH on a lot I was looking at and he basically talked me out of it. We ran through the numbers together and determined the lot is about $50k over priced. As the conversation progressed, he asked if I'd be interested in partnering on flips. 

So I'd like to understand what would be his incentives? 

How would we structure those deals?

Are flips typically all out of pocket cash or can you finance them?