Just a few questions

I can only afford a g3 ibook. I want to comfortably run osx itunes and some games....(some)

1) If i want the above, what specs should i be looking for?
2) How much would be an appropriate price for a used one.
3)If i wanted to run halo on a g3 what specs would i need?

Please and thanks. I really want to switch to Mac

AND NO IM NOT GETTING A MINIMAC

Halo requires a 800 mhz G4 or higher so you are out of luck