Creative financing choices to purchase SFR for myself

[Carl N.]

As I am reading around I am wondering if this strategy occurs or is even possible.  In buying a home for myself if I notice a house that has been for sale for a while or is for sale maybe through craigslist is it possible and what advantages/disadvantages to each side does taking over an existing loan present. 

Example:  Home has been on the market for a while at $1,750,000.  Brand new home purchased 18 months ago for $1.6M.  They are saying it is a motivated seller.  Is it possible and beneficial to the owner at all for me to present taking over their existing loan?

Thought process on my end is I am picking up a house appraised most likely around 1.7M for under 1.6M assuming they have been paying their mortgage and put money down.  Wouldn't then I be actually obtaining the home for (1.6M- whatever they have paid down so far)?