like to know before purchasing.
This has been extensively discussed elsewhere, so to briefly summarize:
Bryce 7 does not work on OS X 10.7 (Lion) or OS X 10.8 (Mountain Lion).
DAZ have said that they do not plan to fix this until the next Bryce development cycle.
DAZ have not said when the next Bryce development cycle will begin.
You should be able to run the Windows version of Bryce 7 on Windows under Parallels or VMWare on Mac.
I don’t know if anyone’s tested the Bryce/Windows/Parallels combo on a Retina-display MacBook. My guess is that it should work as well as that combo works on any other MacBook, but - because the Bryce UI is all based on fixed-size bitmaps - it won’t look as pretty as a new Retina-ready app.