I got the personal license of Mathematica for Mac a while ago and thought the price was reasonable for such a powerful system.
The only thing that was driving me nuts is that Mathematica does not work properly on a Retina display, which of course is a shame as text and graphics would look gorgeous. Support for that is only planned for the next major version, according to Wolfram (http://mathematica.stackexchange.com/a/30104/10565).
I recently found a hacky fix: http://mathematica.stackexchange.com/a/21158/10565
With that, Mathematica now looks fantastic on my MacBook Pro's built-in screen.
If I increase RAM, I get a black screen when launching the machine.
If I try -vga std (hoping to get better resolution) I get an error.