I would agree with what George here has already stated, and I'll even venture to make some additional recommendations. If you can provide something of value to the table - such as bring in an end cash buyer who can close - I suggest simply offering a no-obligation joint venture agreement to be able to market his property with a 50/50 split of the wholesale profit if you do bring in a buyer. If you do so, the spread is obviously much more appealing to a potential buyer than marking up the price and involving multiple middle men into the deal.
I would focus primarily on building relationships with cash buyers; and a few quality ones, doesn't have to be hundreds. I've learned that cultivating a few of these types of relationships are much more beneficial in the long run as you know exactly what they want AND you'll end up essentially 'shopping' for them, which we all know is a much more streamlined and methodical way to approach the hunt for deals than doing it backwards. Learn the numbers that work for them, the types of properties they'll close on, and most importantly…the specific areas in which they're looking for new acquisitions. With this 'shopping list' you will position yourself 10 steps ahead of your competition by zoning in on your market and knowing EXACTLY what you need to offer on a particular type of property in order to make your desired profit.
Forgive me for going off in a tangent. Moving forward, the reason I'll reiterate the topic of AREAS is because areas are also very crucial to the overall VALUE of the property - it isn't simply the numbers. The best advice anyone can give you regarding this deal is this: Do your due diligence! Ensure the specific area is one that is flourishing, or at least one that would attract decent tenants. If it is located in a part of the city that is overwhelmingly unfavorable then I suggest not wasting too much effort on this deal as there will more than likely be a deficit of cash buyers, but more importantly, there will be no one interested in purchasing properties in this area no matter what the spread.