I've decided I'm going to grab a Air France flight straight into CDG... it's maybe $15 more, but I'm sure I'll be saving several times that in not having to get a taxi from ORY to CDG. As far as flying in and taking some time, my flight in to GVA arrives a little after 5pm, and there aren't any good reasonably-priced flight in to Paris the same night. So I'll fly in that morning, and experience the city (and for more than a few hours) another time.

Thanks for the help, everyone! You've all made my life much easier.