Well with Ebay you get a bigger audience, and if they're quite desireable you might be able to get into a good bidding war situation. However you have to pay a seller fee, and you have to handle payment arrangements on your own.
You could try half.com, affiliated with ebay. You set your own price, there's no seller fee, and the payment is handled through them. I have sold some stuff on Half.com and it worked nice. Check and see what similar items are going for on ebay and half before making your choice I would say.
Although, the main FOX.com page says "24" will air at normal time, if you go into the main "24" page for FOX.com, a pop up says "Due to the Presidential address on Tuesday episode #18 will air Sunday. April 18th 9/8c".