Advice??? 50K needed for down payment then 0% owner financing

[Ty Pierce]

A friend currently owns a rental property with renters currently paying monthly. He wants to sell this property yet wants 50K down then will finance remaining at 0% Comps on the home are currently 166K and it needs about 20K of work in rehab.  He will owner finance this property at 0% interest on a 10 year note.  However, he wants 50K down up front to do so.  I sold him this property a year ago for 165K.  Currently, there are renters paying him $1650 monthly on this property.  After negotiating we agreed on a sell price of 130K.  Any advice on attaining the initial 50K?  I don't want to pay a private investor or hard money lender a higher interest rate which would squash the agreed upon 0%.....so basically after the 50K initial deposit I would be financing approximately 80K at 0% interest and there are already tenants living there.  Any direction is highly appreciated.