Personally I use the following site as a reference. I can't validate if the prices listed are accurate. They seem to be a bit less than the typical prices being offered on, for example, kijiji. Though this could be in great part to most mac users being unwilling to accept the true present day value of there mac. However, with that being said, macs do have a good resale value. In your case, with it still having an active warranty, it adds heaps and mounds to the deal in my opinion. If you provide the potential buyers the S/N to the mbp (and instructions on how to look it up on apples website to verify the warranty is still active) it might help in getting the price you want. Providing the S/N, in my experience, doesn't jeopardize anything because the computer & applecare is registered in your name. Just be sure not to give out the applecare agreement number. The selling prices vary considerably.
http://www.mac2sell.net/
Message was edited by: MacLovin54321