An investor offered to sell me a note he has

[Thembi Moyo]

Hi BP members,

A real estate investor offered to sell me a note which he has between himself (functions as bank) and a buyer of property.  he offered to sell me the note for $45K. here are the details of the deal:

Current balance of the note is $46K with 12 years left to pay off

Int rate is 9% so would receive $815 of P&I and escrow from borrower

The value of the home (according to Zillow) is $70K.

First, what are some of the things I should make sure to consider and evaluate before making a decision on this. 

The buying of notes is fairly new to me since I'm more of a buy & hold investor.

Any advice would be greatly appreciated.

Thanks