Even after collecting for years , some of the prices of those banknotes still are hard to understand.. I probably have a few thousand banknotes from more than 230 countries .. Some are very old from 1792 french revolution, some are from countries that lasted only a few years/decades (say Bohemia and Moravia, German East Africa or the Keeling Cocos Island). But none of those are particulary expensive .. or very hard to find.
No ..after checking it seems that my most expensive banknotes is a 2008 one.
Is it a high denomination then ? nope.. not even .. as for its face value it is worth 1.5 USD ..
Is it a special edition then ? yes, although about 6 mio of those Chinese 10-Yuan Olympic edition were issued, the demand far exceeded the supply ( http://bit.ly/hagyB8 ) and prices went up the scale and nowadays one would pay over 500$ to get one !! I was very lucky as this one was a gift for me.. I did buy the HongKong and Macau edition though to have a complete set.
Don’t get me wrong, this is a very nice banknote with a nice illustrations . but sooooooooo expensive ..
As for me now, I prefer to hunt for those 19th century notes that you can find for less than 10$ a piece

Well, its been a great month for the website. Aside from some advertising, which is an unfortunate reality, I have added a bunch of content and now the website features 34,350+ banknote listings, 3,650+ banknotes with images, 21350+ catalog values, 5,550+ eBay sales values, and banknotes views just under 30,000! More importantly, however, I have recently added two authors to the blog: om007 and Babar. I can’t wait to see some blog entries from these two. And for those of you who are visiting the blog only, remember that the main website is www.RealBanknotes.com.

I am currently adding some eBay sales stats to the website, and I have noticed that, as of late, modern issues of Italian money are going for a very good price if you are not particular about buying only uncirculated notes. I mean, Italian notes are not that valuable to begin with, but I know that they were going for more money a few months ago then they are now. For example, I purchased picks 111c, 112a, 112b all in EF-AUNC condition for $7, $11, and $9 respectively in March or April. I have just come across these notes on eBay: pick 112a in EF condition that sold for $4.75, pick 112b in EF condition that sold for $3.18, and pick 111b in VF condition that sold for $2.16. I guess they’re good bargains for now, but not profitable to sell.