Just a couple things, Gazelle essentially provided a wholesale quote. They are going to resell them either as units or for parts through whatever distribution. You never get the retail value of something through a tradein program.
The SSD sells for $125 new. I couldn't find that exact model, but the newer ones are roughly that price. That is new. The OP is selling one that is used and a couple years old. You can mark labor and whatever you like into that equation. It doesn't mean a potential buyer will pay for it.
As for refurb units, where are you getting your numbers? I was
apparently only $30 off on that model. 2012 models come up around $1300-1400 frequently. Once you're up around $1500 you can generally find a better purchase with a warranty. Depending on what is important to you, the 2012s have a far better gpu than the 6490m in the model mentioned, and they have usb3. It depends on your priorities, but I think it would be a terrible buy at $1500.
The refurbished unit I showed was $1230. They wouldn't contain old batteries and chargers. They are more like $1000 used if that, at least in LA. The older OCZ drive is probably worth $60 as is. The HDD is a couple years old. I wouldn't add much for used drives in general. Right now the key sticks. If the OP has it cleaned, and that results in a completely functional keyboard, that's different from saying a cleaning may or may not fix it. You're deriving figures in the most ridiculous way possible. Someone was dumb enough to pay that for yours, and you benefited from it.
I would agree that you tend to do better selling locally. Buyers can look over the machine before buying. You do not have to deal with ebay fees, disputes, or anything of that sort. You don't have to deal with tradein rates from a company like Gazelle.