Imagine Dell selling dull gray OSX computers for half the price Apple does?
Isn't this meme past it's sell-by date? Can anyone provide a link to this Dell machine which provides the same performance and features as an existing Apple machine at *half* the price? Oh, didn't you mean *half*? Were you just exaggerating for effect? Did you mean that there's an Apple premium? Perhaps you meant that some people are willing to pay a little more than bargain-basement prices because someone's put more than the bare minimum of effort into bolting together a pile of commodity parts and making sure the damn thing works without the user spending un-costed hours chasing down drivers?
Any given program will expand to fill available memory.