I generally don't like to go less than $10K-$20K on a downpayment to be sure the buyer has skin in the game.I ABSOLUTELY recommend you work with a Real Estate Lawyer and/or Title company on deeds, promissory notes, deed of trust etc... to make sure everything is drawn up correctly and filed correctly.

Wish I had a cleaner answer, but everyone is going to want you to have skin in the game. 

They don’t have skin in the game.

We don’t require any down payment (unless it’s your first deal and you have a deal where the rehab + purchase price + closing costs are under 70%, we may lower how much we loan you so that you have skin in the game).

They have more skin in the game then you do.Make sure you get clear title.

It was recommended to me that I collect a refundable performance guarantee fee from co-signer so she has some skin in the game.

Many wholesalers have no skin in the game and if they can't find a Buyer--tough for Seller.

Make sure you verify the labor and material costs you are paying, I mean absolutely sure because you really do want to understand his skin in the game. 

Wholesaling is mostly like any other market with a low barrier to entry: it's filled with people who have no skin in the game. is it possible?

In other words, gold mine is mostly for builder since they are taking the biggest risk and land owner get the least since they have least skin in the game.