I have not used either, but you can check out:
www.cardavenue.com
www.swapagift.com
I do think there are fees ~ somewhere in the area of $4. It might be worth it though to get something you'll actually use. With ebay, you risk not knowing what you'll end up getting. With these sites, it's pre-determined, and your posting lasts 90 days, I believe. (You don't pay every 5-7 days...)
Good luck!