We therefore hold these truths to be self-evident...

1. You spend your own money buying something for yourself—you therefore try to get the best possible product for the best possible price.


2. You spend someone else's money buying something for yourself—you still try to get the best possible product, but you are not so concerned about the price.


3. You spend your own money buying something for someone else—you are deeply concerned about the price, but you are not nearly so worried about the quality of the product.


4. You spend someone else's money buying something for someone else—in which case, who gives a shit?

with thanks to P.J.O'Rourke and Milton Friedman.