I recently went to the Gun Runners and was buying various ammunition making components (Cases, gun powder, and primer) and everytime I went to buy all of them at once, the game crashed on me.

Yep, it's an issue with the cases. When trying to buy more than one case, the game crashes. You literally have to buy one at a time and exit the dialogue completely, then re-enter dialogue if you want to buy more than one case. It's hellishly irritating.