I live on a dead end road out in the country. There are about 7 houses along this stretch of road. Between the 7 houses I would estimes there is over 100k of ammo. Plus, the guy that lives at the dead end of the road has a gun room, not a gun safe. You can walk into this "safe" and he has around $75k worth of guns.
My brother built one of them off the back of his 35'x75' heated shop. About a 20'x20' room. Has a 1/2 bathroom built off the back of that with a generator to run the whole shop in case power is lost. Has a big poker table set up in the middle of it. 2 huge gun safes built into the west wall opposite the door. With another 4 just outside the door in the shop. One safe has nothing but hand guns of assorted caliber and ammo. Probably 50 or so. He built his safe room about 5 years ago. He's been collecting guns since he was a kid. He's 45 now. I couldn't even begin to guess how many he has. Makes me look like I have nothing. He's slowed down on buying guns the last few years, but still manages to add one here and there if he stumbles on a good buy. He owns a tire store in Williston, ND. Has actually acquired guns and ammo from people in trade for the price of tires and working on their vehicles.
He is not nearly as much of a doomsday prepper as one would think with that kind of stockpile. He just loves guns and collecting them. Figures it's just a good investment as guns don't lose their value if you take care of them. A lot of his guns have never been fired, or have been fired very little.