My dad was notoriously cheap, and all his screwdrivers came from the 29c bins on the hardware store counter. Naturally they all rounded off quickly.
There was this restaurant we would go to sometimes on special occasions (like Easter) that had a "farm" theme, with paths and fences and old equipment as decoration, including a giant old manual grinding wheel that actually worked. Kind of like this:
Whenever we would visit there, my dad would load his pockets with his rounded-off cheap screwdrivers, wait until no other guests were nearby, and use the grinding wheel to square them up.
This worked for him because he would only use slotted screws, never Phillips. Once I asked him why, and he said "Because the heads strip so easily." I guess that's not surprising, because nothing ruins a Phillips screw head faster than a worn out tip, and nothing wears out faster than a 29 cent Phillips screwdriver.