Preordered SP3 - Need to sell Macbook Pro

I preordered the Surface Pro 3 and am very excited.

Currently I use a 2011 MacBook Pro 13 inch, which I upgraded with a Samsung SSD and 8GB of RAM. I run Windows 8.1 on it, but obviously it also runs OS X.

My question is...what would be the best way to go about selling it? EBay? Craigslist? Also, how much do you think I could expect to get for it? It's in great condition, a few scuffs on it but nothing major. Everything still works flawlessly. I am just looking for an ultraportable to be used between work and home, and I fell in love with the SP3 form factor.

Thanks for any help or advice you may have! :)