If you go to the PI website there is a Product FAQ link to click on. One of the FAQ is "why 171 Euros" and the answer provided is:
At the date of the first commercial release of PixInsight, 171 was the largest integer number in EUR less than or equal to 250 USD.
That is what we told to our accountants. The actual reason is: 171 is a prime number, a palindrome, and the sum of its digits is equal to nine. It is definitely a magic number with very special properties. Sorry, we can't tell you more or we'd have to kill you.
Sorry, but 171 is not a prime number; 171=3*57. Can we really trust people to get the complex mathematics of PI correct if they make this sort of elementary error? Or are they just testing us?
Geoff