how much should i sell my computer for?

Refurb prices go anywhere from $150 - $300 which I assume is far less than what you paid for it and also far less than what it will cost you to replace your machine.

If it does what you want / need it to do, then you should just keep it since replacing it will cost a lot.

Take the amount which you paid for it. Take off 30% per year that you have owned it, so if it was manufactured in 2010, it is worth a maximum of 40% of what you originally paid for it.

Computers are one of the fastest items to drop in value. Its 2 years old I would say maybe 1/4 of what you paid or less because PC prices are always dropping and technology always moving forward

About $150 if your lucky, that the online refab price for that model