What makes you think you will do better than them ? If its not rented you will be on the hook for the monthlies +++ The 5% (apx) equity that they Had dissapeared, better to cut the loss and run.
Also if its an interest only mtg , you are not getting anything paid off the principle. Your payments are $20k per yr. apx in 5 yrs you have sunk apx 100K in the house, how much do you feel it will appreciate in that time?
Sorry to be so blunt , but this is just the tip of the iceberg. A lot of people got into real estate speculating without knowing dick about it , assuming there is no end to the up cycle.
