The most valuable banknotes in current general circulation (exchange rates as of April, 2011) are :
For currency collectors, the most expensive banknote listed in The Standard Catalog of World Paper Money is the USA 1890 1000 Dollars (P350) which is listed as $1.1m in Extra Fine quality.
Until 1969, the United States had a $100,000 Dollar banknote, which is still legal tender meaning that even a tatty example is worth AT LEAST $100,000. Because of the rarity, an uncirculated example would be worth considerably more.
The Bank of England has non-circulating notes used for internal accounting with a face value of £100,000,000 or $160 Billion Dollars.
In 2000, the Bank of Thailand issued 1,998 500,000THB notes to celebrate the 50th anniversary of King Bhumibol and Queen Sirikit. The notes are meant for collectors, but it is still a valid mean of payment. 500,000THB=$15,000.
The worlds most expensive shell would probably be the sunrise shelll seliing up to 1,000 dollars.
the world most expensive phone is a smart pair phone
It might be a Choprad
a motor bike
the hope diamond is my answer
Harrods of Knightsbridge.