Hmm. What makes you so sure that the money changers in the temple were operating an efficient market? Having learned the story in Sunday School, I've always assumed there was corruption / collusion.
Anyway, your point that accountants shed light on situations that thieves would like to keep hidden is certainly true, with the notable exception of that Enron situation, where a few of them were participants.
BTW, I'm very happy to see you are posting again - I enjoy reading your opinions.
The Sunday school version, as I recall, was written by those with a vested interest in justifying the act. But you do pose an interesting question -- I seem to recall reading somewhere ages ago something to the effect that the money changers bought licenses to operate there; competition was limited, the money changers also kicked back a percentage to the temple, so it might not have operated all that efficiently. That doesn't mean, though, that the money changers didn't calculate the exchange rates they needed to pay off their licenses and tribute and still make a profit.
And let's not forget that it wasn't the money changers insisting on donating shekels to the temple. Perhaps the real moral of the story has nothing to do with economics and everything to do with inclusion. Only the currency of the Jews could be donated to the temple; perhaps Jesus was symbolically identifying foreign money with foreign people -- that all should be allowed to enter.
In any case, given the Mormon story, it was too good of a metaphor to pass up.