You're getting voted down but this is a pretty good question! I had a tool kit in the Marines that was a basic split case with DeWalt looking hand tools and a

You're getting voted down but this is a pretty good question! I had a tool kit in the Marines that was a basic split case with DeWalt looking hand tools and a soldering kit in it. The thing cost somewhere on the order of $60k and replacing individual parts was often more expensive than the sum of the collection. I constantly had to inventory the thing every time I took it out and I'd never let anyone use my tools or leave them laying around. The reason is that military tools and parts are built according to a spec and often in batches. That spec has to be reaffirmed for every batch and is often specified within the item spec. There's pretty normal specs in there like size and thread count, but then there's other that require destructive testing like tensile strength, material composition, heat tolerance, etc... When you make a big order the price per unit is pretty cheap because one destroyed item per item in the collection is amortized across the rest of them. When you order a single one they make one plus one for each destructive test. One of the most memorable examples I can think of is that I operated a special truck in Afghanistan that cost ~$1.5M. In order to build and deploy that one truck they built 4 more including all internals and hit it with rockets, explosives, and bullets to durability test the configuration of the internals. In the end, one $1.5M truck is actually $7.5M in order to ensure the safety of everyone inside.