Option$ when your flip does not appraise to your agreed price

[Nick Cucci]

Hey BP! I am just about finished with my first flip. We made SO many mistakes (budget blown, took way too long), but the end result is a beautiful house in an up and coming neighborhood in New Jersey. We have a buyer and an agreed upon sales price. We're about to get everything moving and I have a suspicion that the house is not going to appraise for the agreed upon price. I don't want to abandon the deal, so I'm considering my options. I need to pay back my hard money lender asap, so was considering holding a portion of the note so the sale can still happen. Has anyone done this when there is a traditional mortgage involved? I imagine a lender would not be very enthusiastic about me holding a small note on the property, but wondering if anyone has dealt with a similar scenario before? 

I was also considering refi-ing the property, renting it for 2-3 years and then selling at a higher price. It is in a neighborhood that will be trending upward for the foreseeable future, but I would prefer to sell so I can invest in other areas. 

Thank you for any insights!