Yes, walk. No point throwing good money after bad.

If you add all the ownership premiums you’ve paid over the last 3 years, then the losses are daunting.

The questions you need to ask:

1) Will future appreciation pay you back all they ownership premiums and opportunity costs you’ve put into the house over the years?

2) What is the likelyhood of future housing appreciation to occur? Are you willing to take the risk of putting more into the house and getting nothing in return?

3) How old you are now. If you’re 50yo, then there’s not point trying to hang on. You need to move on with your life. And the odds of housing appreciation bailing you out are nil.

If you walk now:
a) You limit your losses to what you have in it already.
b) You can save the amount over and above rent for a future down payment.

If you have a 10% or 20% down-payment on a future purchase (which very few people do), few lenders will turn you away. It’s gonna get so bad that lenders will not longer look at foreclosure as a bad mark on credit history.

Remember, the bank looks at your as a dollar sign. You should look at your relationship with them the same way. Life is a two-way road.