You wait 3-4 years after collapse then you start offering banks insane discounts on all the houses and land they are holding, or the trustees if bank failed. My grandfather worked his hinny off after World War One in construction in Chicago, he never believed in banks but buried it in concrete in basement, LOL, come 1933, he started buying blocks of land on edge of Chicago, at one point, he owned edge of what is now O'Hare airport, but back before World War Two, some of it was apple orchard. And the name "ORD" call sign for this airport was based on it being before Orchard Air field, in early 1942, government started building war planes. The name "O"Hare" was from Naval aviator who became the Navy's first Flying Ace and he became the first naval recipient of the Medal of Honor, he was eventually shot down by Japanese. That is your History lesson for today. Cash is king any time, and time to buy land, paintings, rare coins and stamps up in depressions.
There's lots of websites dedicated to this. Just use Google. For example, food prices will soar to prices that only the rich can afford to buy them and that in itself will create riots and looting of the food supply. I know one guy so paranoid about such...he has cold storage in his basement that's large enough to hold two years of food supply for his family and its 25% full. He saids that in case of a economic/financial collapse in which grocery prices soars to levels that only the rich can afford...he's go to 100% full storage. I wouldn't be surprise if the guy will someday buy Gold bars. Yeah, his camping survival equipment is unreal.