Advise on proper: Seller carries loan for 3 yrs

[Alex Short]

I have been a offered a opportunity from a close family friend to purchase there rental property.

Currently the house appraised for $45,000

I will be buying the house, the seller will be carrying the loan for 3 years and I will purchase in full in 3 yrs.

Numbers:

$3000- down

$300- paid to the seller each mouth ($200 towards loan/ $100 paid to seller)

$32,800- what will be owed after three years

In the mean time I will rent the house for $700 a month and get profit. 

Any thoughts on  this deal or what I should look out for?