As a starting point, you can check Mac2Sell, eBay, or Amazon for prices of similar models, to get an idea of what you may be able to charge. Then adjust your price to account for condition, configuration, remaining AppleCare coverage (if any), etc.
Also, you can change your thread title by clicking the "Edit" button on your original post, then click "Go Advanced" and you will see where to edit the thread title.
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