Ditto craigslist. No need to join. I've sold several things there. Only do cash and carry. If you sell it for only what it cost you, inc. shipping, you will definitely make some little girl's Christmas and you won't be out any $$.
ADDED-I just checked my local craigslist and all I can saw is WOW! Christmas sure does bring out the greed in some people. Looks like most are asking $40-$45 for one hamster. Not a bad profit on a $10 toy. The worst one is asking $275 for one hamster and 4 additional accessories. Really, are you kidding me! I can get one hamster and accessories for DD or I can get her a Wii, plus a few games, for about the same price? What should I do? Hmmmm....I think I'll go for the game that will give her (and the rest of the family) many hours of fun, not the toy that will be selling all over town in a little while and more than likely she'll only play with it a few hours.
For those who are profiteering on the hopes of little kids, for shame. I know OP isn't looking to do this. So this is directed at those others who are buying up all the Zhu Zhus they can and charging so much more. I haven't looked at ebay but I understand they are going for even more there. I only hope when the market is flooded with all those little hamsters those who bought all that they could will be stuck with them and that the stores will not take them back. That's my Christmas wish
OP, good luck on whatever you decide. If you don't want to sell on craigslist, etc. you might ask your friends and relatives if they know of anyone looking for what you have.