Wholesaling 13 properties in a package deal

[Stephen Bowman]

I'm new to wholesaling, but have a great deal we're working on closing. Does anyone have any advice on wholesaling package deals?

Let's say we had 13 properties that a landlord is willing to let us put under contract for a total of $710,000 and we have a buyer at that price. We want to charge a mere $15,000 assignment fee. The properties still have a $250,000 commercial loan and the buyer is getting conventional financing on his end to close the deal. 

Would we have to open escrow for each house separately? 

Since the buyer is getting financed, I'm assuming each house would have to appraise for a certain amount of the entire deal to go through? 

Would we have to have multiple contracts with the seller and with the buyer or just one for each? 

Any other pitfalls we should look out for/is this even possible?

Thanks!