Seriously, guys. Are we really on the fifth page of discussion about grapefruit? I'm guessing that this poor guy did not have any idea that a gesture that he might have thought would be a considerate one would engender this much impassioned discussion.
Honestly, I think that it's perfectly acceptable either way. Yes, most people I know that bring excess food to a place of work bring it intending to share it free. We all know each other pretty well. But I wouldn't consider it my place to judge someone who would ask for compensation, especially since the amount he's asking is more than fair. If I don't like it, then I don't have to buy it.
I don't think that we need to expend this much thought and energy into either justifying or punishing this poor guy. If he's a moron for other reasons, so be it. If he's a great guy, other than for this one supposed flaw, then those who are judging him for it are probably not such heroes themselves.
And by the way, I would like to point out that the fact that this thread has devolved into penis portion size had nothing to do with me. This time.