.-  Your are only buying part of the loan- the seller retains what is left of the payment schedule after you are paid.  

@Mike D'Arrigo - I agree with your math, plus again, you retain full control by being the sole owner.  

Or if it is our staff I retain time and expense records in case it's ever challenged.  

The managers we work with have actually told us that they're making 40% more profit with our model while retaining more control over how they're managing their properties. 

I'm starting a $20k retaining wall next week... 

At that point you can afford a lawyer on retainer as an employee.

just going to make rentals that much tougher to qualify for and retain.  

They make their living by annoying people who don't want to sell to find a few that are desperate or uninformed enough to tie up their property in a contract that the wholesaler has no ability to actually execute and giving up equity they could have retained to a person that adds no real value to the transaction.

I gave the sales rep the benefit of the doubt and asked him, "Of the people that join your program what percentage do you retain?

Something to consider in your cost analysis.My end goal is to build and retain apartment complexes, I'm not there yet.