Where to sell my brand new, unopened 15" macbook Pro?

Wondering where to sell my brand new, unopened 15" MacBook Pro? Got it through school with apple care, upgraded to 512gb, and lojak. Don't need it and haven't had any bites on ebay or craigslist. As I got it through school and did not purchase myself, I cannot return it to apple. Any help would be appreciated. THANKS!