How much can I sell my bike for?

Last year I bought a 13 inch frame hardrock specialized. It's a pretty sucky bike, especially now that It's too small for me. No disks, and junky shifters. Although it doesn't work for me, i thought someone else may be able to use it. I was thinking about trying to sell it on ebay and was wondering how much i could pass it off for. I'm trying to save for a giant Yukon FX-----need about 400 more bucks. Although that's about how much i bought it for so i doubt i can sell it for that much. Anyway, an estimate on how much and where to sell it would be greatly appreciated.