Interesting notion, but a couple issues:
- anyone who could afford to buy your gold wouldn't need it
- why would you even bother to spend the whateveryougotforyourgold on your mortgage? The bank would be unlikely to foreclose, I would think.
Plus, here's something whacky, given how many times mortgages change hands and how the mortgage companies track them, in a SHTF situation with any sort of internet sabotage, they might not even be able to figure out who owes what. Anyone remember that terrible Emilio Estevez movie where he kinda plays Robin Hood in the west by ruining records of farm mortgages, then it ends up that it was all a fantasy? (Oops, spoiler alert.) It'd kinda be like that, I think.
The mortgage holders would have a really difficult time foreclosing.
Need vs. Want. People who could afford it will always want it.
It's not about fear of foreclosure... it's about paying off a hundred grand for pennies on the dollar, relatively speaking.