Purchase wholesale property with mortgage

[Joe Young]

I found a deal on a duplex that is under contract with a wholesaler.  The wholesaler is only accepting cash offers due to banks not allowing / not financing assignment fees  (this is what he told me) .   However he is OK with a 30 day close which gives me time to arrange financing.

Can I just pay him his assignment fee in exchange for the purchase contract?  If so what is the right way to do so? 

Just to make things clear he's asking $105 for the property.... Can I write him a check for $5,000 and take over the right to purchase the property for $100k?  

I have the cash but it is best used elsewhere.