One of the most commonly abused glitches found in Bethesda games are the ones that revolve around some form of item duplication. Skyrim had it and now it appears Fallout 4 does as well.
How Does It Work?:
As far as money glitches go, this one can sound a bit complicated at first. Luckily for you, I’m going to break it into bullets.
Find a vendor that sells ammunition. (This doesn’t work on all so jump around a bit) Bring every piece of their most expensive ammo over to your box in the trade but don’t buy it yet. Send a single round of that same ammunition back to their box. Again, no transactions are actually happening yet. Now sell the vendor any amount of that ammo, as long as it’s not a single round or the entire amount. This should now cause the ammo to remain in your inventory, while the caps begin to rise. You can spam this as much as you’d like to get your caps up before finally selling.
With this glitch, you can buy out everything from a vendor, then get every penny back. This works with enough vendors in the game, that you can easily obtain more money than you’d ever care to spend.
Note: As with all notable glitches, this one is bound to be patched at some point or another, so if you’re planning on exploiting it, much like the Cryonator glitch, get to it before it’s too late.