Why are there so many acorns on an Oak tree? Same reason, to improve the odds that at least one manages to make the trip and carry on the species. Nature uses overkill on a lot of things.
Assuming you mean the conversion of Linden Dollars to U.S. Dollars (or some other currency): That can be found in the LINDEN EXCHANGE on www.secondlife.com The average current exchange to USD as of...