I'll throw out the question and then give my thoughts about a potential answer, which I am not convinvced are correct.
Where does the phrase "right on the money" or "on the money" come from? (I thought I was wrong after being second-guessed, but it turned out my answer was right on the money.)
The phrase has an equivalent meaning to "on the mark," "on target," "on the spot," &c. My intial thought was that this phrase comes from horse racing vernacular. When a horse finishes in a position high enough to provide a pay-out to a bettor, it said to have "run in the money." Similarly, when the horse does not place high enough, it said to have run "out of the money." These make sense, but they are not exactly the same as "on the money." Similarly, "on the mark," "on target," and "on the spot," seem to be related to target shooting, archery, artillery or some such activity where these phrases have a certain logic. But, no one (that I know) uses money as a target for firing projectiles at. I guess, when it comes down to it, it's the "on" in the phrase which throws me. Does anyone have a guess as to this phrase's provenance? Is this phrase even used in Britain, or is it purely American?