The jewelry store I work for in downtown DC (Tiny Jewel Box) does a fair amount of radio advertising this time of year and we get a great response from it. I don't have any of our contracts handy to give you pricing, but I'll make some calls and might be able to give you contacts for a few local stations. I'll send you a pm in a little while.

Also, if you've got ad creative available, it might not be too late to do something in print media. Our magazine and newspaper reps are still calling to make last minute offers.