The government is making the killing. They set the official rate, the market sets the actual (unofficial, thorn in the government's foot) rate.
If the pricing difference between official and blue rate surprises you, you'd best do some more homework before coming down. Make sure you realize that Argentina, specifically Buenos Aires, isn't the place it was even 1-2 years ago. Still some fun to be had, but don't come down expecting the "Paris of South America."