I think you should learn a little more about facts before you post.
The truth is that if you purchased the last update after Feb 1 2010 your current 9.1 update is free. The last update was 9.0 in dec 2010. So you may get both 9.0 and 9.1 for free if you updated last time between Feb 1 and Dec 2010
This is all written here.
The 9.1 is a major update with lots of new functions for us who need them. You may not need them so whats the problem. Just do not update but wait for the next update. Thats all up to you .
And € 45 for the update is really not much for all the work Joost does.