An expansion pack seems to make more sense, cost-wise. The cards could be low-cost produced (with high donated labor; where might you get that?
) but you'd still have to figure out the boxes.
One other thing you'd have to investigate, is what kind of legal requirements there might be. I'm not sure if the Trivial Pursuit makers could ask you for a licensing fee for an expansion pack.
To me it seems the attractiveness of such a game would be whether it has universal recognition questions or too many local recognition questions. I know a lot about MI teams and some about the acknowledged powerhouses. But I don't know much about teams in GA or MN or NJ, just to pick a few examples. Would I be getting a whole lot of questions wrong? I wouldn't play it very often then.