Can you do all the image/signal processing stuff with the home edition?
http://news.ycombinator.com/item?id=382986
Q: How is Mathematica Home Edition different from the professional version of Mathematica?
Mathematica Home Edition is a fully functional version of Mathematica Professional with the same features.
http://gregmankiw.blogspot.com/2007/12/moving-toward-perfect...
This is an attempt to get deeper penetration into the hobbyist market.
Price discrimination* (http://en.wikipedia.org/wiki/Price_discrimination) is profitable if you can pull it off.
*Don't let the scary name put you off; everyone price discriminates if they can. The best price discriminators in the world are American universities.