After the big story on the 2008 50 pesos error with country name spelled Chiie, it turned out a 2009 specimen also exist. Apparently, after the error was made public a few 2009 coins were also struck, but were destroyed. A few made it out and I have one. Nice collectable.
I remember when the 2008 coins swamped ebay, starting at over $100 each and going down to $10 within a couple months. I think the 2009 was done on purpose, an assisted error.