Skybus, the ultimate in low-cost-carriers within the United States is selling seats on many routes for $20.08, just in time for the new year. Oakland-Columbus is the only route Skybus operates from the Bay Area, though many other routings throughout the U.S are included in the promotion. The price of $20.08 is each way + tax, so it will run you about $60 dollars for a round-trip ticket to Columbus, and checking their website this morning, it seems there are plenty of seats left.
Visit SkyBus for more information. Book soon, these prices won't last.
Also consider: Top 10 things to do in Columbus (From TripAdvisor)