If staying in the home for that amount of time sounds unreasonable, you may want to get out now. However if you feel like you can hang in there while you get the value back then stay and enjoy the home.
First rule of investing: buy low/sell high.
It's going to take too long and too much mortgage-money to get your home back to where you began. (average non-bubble'd increase is +3%/yr - inflation = a wash)
In the meantime, the neighbors house is half price and it'll be up in value to where you began.
You will not have any equity - and your neighbors house will a 40%-50% gain in value (someday but not in the next 5-10yrs) Your neighbor can access the benefits of HELOCs and such - things they can use to secure a college education or retirement.