$200 in cash at a rest area one night. Snap-on 3/8 in. socket,drive, and extension. Square nosed shovel, hammer, vise grips, pliers, phillips screwdriver, HVAC tools, and many dead animals.
The best was when I was a package driver. At one of the electrical supply warehouses I delivered to, they had a recycle bin full of odd lengths of romex, and other electrical wire. They said I could have it. I was able to save about $200 on wiring alone when I wired a sub-panel, and my "man cave" in my garage.