The part you should research is actually getting that for your Mac. My buddy recently tried to sell his MacBook Pro on eBay and was inundated with offers and a final sale price above his asking price.
The problem was getting the money. Most PayPal accounts had been compromised with buyers asking him to ship it to Indonesia or some other 3rd world country.
He never got his money and all the scammers outbid serious bidders.
The Amazing Resale Value of Your Mac