Man, you guys should become lawyers and open your own firm. You could call it "Wrong, Wronger and Wrongest"! Here's the true story of the derivation of the phrase "Waste not, want not":

The monetary unit of the ancient land of Mucustan was the "Tnot". I know it's a bit difficult for modern English speakers to say "Tnot" but, believe me, those old Mucustanians had no trouble at all with it.

Mucustan was situated along an active caravan route, which pretty much guaranteed that some traveler would introduce a freshly mutated variety of the common rhinovirus into the Mucustanian population on a weekly basis. As a result, all Mucustanians had perpetual head colds. As you may have gathered, the country's name was derived from its people's strong tendency toward runny noses.

Now, Mucustan was possibly the poorest country in the history of western civilization. It had absolutely no natural resources and, even if it did, it wouldn't have made any difference because all of its citizens were always down with colds and would have had to call in sick anyway. So, the Mucustanians got by in the only way they knew how, by selling the only thing they had plenty of. Yes, you guessed it, they sold mucus to traders with the caravans and the traders took it to the city where it was processed into fertilizer.

Being such an impoverished land, there was only one working scale in all of Mucustan. It belonged to an old man who lived in a shack my the caravan road. Other Mucustanians would come to him to have their mucus weighed so they wouldn't get shorted when they went off to bargain with the traders. The old man charged one Tnot for his services just as the sign on his door advertised: "Weigh Snot. One Tnot."

Thankfully, the story of the evolution of the phrase from its humble beginnings to its modern meaning is as boring as watching paint dry so I won't inflict it upon you at this time.