While it's pretty user friendly and easy to use, and it's accessible commentary is from R.L. Wing's "iChing Workbook"...a $23 book (you can get for less used, on Amazon for example), Change's pricepoint at $39 IS rather high, imho. I'd say $25 would be about right for it.
For the iChing aficionado, worth looking into is the software program "The iChing Connexion X 3.3.1": http://www.mindsports.net/I_Ching_Connexion/ThinkCVersion/
Now, it's much more complex and less user friendly than Changes, it uses the James Legge (19th century Sinologist) iChing translation...hardly intuitive nor all that easily accessible, and it hasn't been updated since it's release nearly 4 years ago, but it's still quite interesting.