Final answer:
The Louisiana Purchase cost was $15 million in 1803, and if adjusted to 2012 dollars, this would be roughly equivalent to $300 million. The purchase doubled the size of the United States and is regarded as one of the greatest real estate transactions in American history.
Step-by-step explanation:
The cost of the Louisiana Purchase was $15 million in 1803, which was a remarkably low price considering the vast amount of land the United States acquired, effectively doubling the size of the country. Adjusting for inflation, that $15 million would equate to a much larger sum today. However, to calculate the exact modern equivalent, one would have to know the specific year they are comparing to, as inflation rates change over time. For example, using a simple purchasing power calculator, if we were to compare the purchase price to 2012 dollars, $1 from 1803 would translate to approximately $20.11, making the rough contemporary equivalent of the purchase around $300 million dollars in 2012 dollars.
However, the accurate value today could be different due to continuous changes in inflation rates. Additionally, the Louisiana Purchase is considered one of the greatest real estate deals in American history because it expansively increased the territory of the United States and fulfilled President Jefferson's vision for an agrarian republic.