JV'ing a JV contract?

[Merari Alfaro]

I have a potential JV situation, the wholesaler who has the contract wants both our company names to be on the Assignment Agreement. He wants to split the proceeds by giving me 30%, is there a way to talk it to 50/50?
None of my buyers got back to me, except one, he has a buyer for me. Problem is he wants to add $2-4K on top of our asking price for his wholesaling fee. How do we go about doing this, and what is the best way to protect myself in this deal as someone who is wholesaling to a wholesaler?