OK, I hope someone can back me up on this...
On the 84-86 run of LMaD I am positive that I saw Monty use a little gizmo I believe he called a "Money Changer" or something like that. From what I remember, Monty gave three contestants a $1 bill, and they could either put it in the changer or take a sure thing prize--typical deal, I guess, except for this device. If a contestant put their bill in, it might "change" into a $1000 bill, or just come out as a $1 bill again.
I know I saw this on at least one episode, and I just remembered today how much I wondered how it worked. Does anyone actually know how this thing actually worked? It had a little crank at the top and looked sorta like a small pepper mill, if that helps.
--Sam