Private Money and Refi question

[Graves Kelly]

My partner and I are in the process of purchasing our 3rd single family  rental property. We were approached my a private money lender who is close with our families. we were relieved because we were both running into DTE issues with conventional lenders.  He is willing to pay the purchase price on a property we have found in return for a small fee plus what he has paid.

My question is if we bought the property for 20% below market value, what are the potential issues we might have once we try and refinance to pay the lender back? Will our DTE still be an issue if we have rented the property? 

New territory for us so looking for a little guidance here. Thanks guys