Don't mean to be rude.

Forget about the past, which can not be altered. In any event, you are about even if you sell at 150k, if you had been taking in 7k a year in the last 6 years.

What I am saying is that from now on, if you keep the property, you get 7k on the current liquitable value of 150k, or about 5%. 
If you sell and take a 350k loan, your potential return is about 26k - 9k tax- 5k hoa - 1k insurance - 14k interest= - 4k/yr.

If you want to keep it for 5 years and sell, you would need at least 5*(7k+4k) + 6%*(50k+15k) (fees for selling two houses) = 94k appreciation to be better off than just keeping the current situation.