But my point was that while the buying power changed over time, the face value did not. If somebody had given you a $100,000 bill in 1934 and you held on to it until 2010, it wouldn’t have retained its 1934 buying power. Your 1934 bill would still be worth only its $100,000 face value.
If that wasn’t the case, I could take an old 1990 twenty dollar bill to the bank and exchange it for thirty three dollars in new 2010 currency. That would make for an interesting economic system.
Okay, so Nemo wanted highest current monetary value (face value times present unit value) for still-legal-tender, including non-general-circulation devices. The answer there appears to be the 100-million-pound British note, if that remains legal tender under British law. Do those still exist, embodying a hundred million British pounds in one piece of paper? (Do the banks holding them carry insurance policies on them?)
If we look only at general-circulation devices–thus excluding the British and American banking devices, and bullion-investment products like the Canadian gold–but are still concerned with current legal-tender value, there is a nominee in the US$10,000 bill. (These haven’t been printed in a while, but some still exist as legal tender. They could be spent, provided the vendor was able to make change!) Any others? If that’s the winner there, I suspect it will also be the winner by the value-at-issue standard I mentioned.
… and a little research shows that it IS beaten. The Singapore dollar doesn’t make that list of the 15 largest currencies, but it’s close and they print a 10,000 dollar note, which Wiki claims as the world’s highest valued banknote (currently printed, obviously). $7754 at today’s exchange rate.
Personally, I’d allow the Canadian 100kg goldpiece as a general issue (albeit an unlikely one). It is legal tender and it is available to private citizens. So you could in theory take one down to a Toronto WalMart and spend it.
I’d be a bit slow to take that tact. Many governments, including Canada, have reneged on redeeming some of their “legal tender” issues.
We used to try to “redeem” the Canadian Olympic coins from 1976. A set of 28 coins had a face value Canadian of $210. When silver was only $5/ounce, we could buy these sets in the US for $150, but you couldn’t redeem them in Canada for $210.
…and buy the entire store. 
Really? I thought if the government issued them with a value on them, like ten dollars, then they had to accept them as legal tender.
Perhaps they should. But who’s going to force them?
A government would lose confidence if it suddenly announces they will not redeem old currency for new, but it’s certainly capable of demonetizing currency and it’s quite common to do so for some countries although I assume they generally give you plenty of warning.
I have two 100 trillion dollar zimbabwe bank notes
FWIW the CBC article is from 2007 and lists the actual value and purchase price between 2.5 and 3 million… considering that gold has recently been trading at around $1400 per ounce… it’s actual value would now be about 5 million…
I wonder if there is any other piece of currency where the “face value” is so much less than the real value???