Mac2Sell isn't really usable as a sole point of reference. It's not often up to date, and I don't know how they calculate their pricing. They're typically not relevant to US pricing.
I wouldn't buy it if you don't actually need a notebook. The price is good. The low end version of the 15" from early 2011 is around $1200 refurbished. Something closer to those specs in a 15" is $1359 from Apple. Add $40 for 8GB of ram and maybe $100 for an ssd. This would be with a warranty. Yes it's higher. Mint just describes physical appearance. It doesn't mean nothing can go wrong, so please keep that in mind. Even then it's not actually a bad deal for someone who wants to use it. You seem to be asking if you could buy it and use it for a year without losing value. I highly doubt that. It might take $1500-1600, depending on how much someone wants it, but I doubt this is the only one you'll ever find in this price range. When the seller purchased it, it was likely well over $2000. I wouldn't count on it remaining above $1000 next year. By then at least some of the macbook airs should be pretty close in performance. The main appeal to the 17" models is for those that want the screen real estate in a notebook and a Mac. Those that wanted one for this reason likely made their purchases as soon as the model went EOL.
I just checked and Apple still asks $1900 refurbished for the 17" models. It's quite a bit more than the 15" models. I expect demand will diminish somewhat when rMBPs become available refurbished. They offer less screen real estate with the tradeoff of a nicer overall display.