My trusty macbook

2006 15" 2.2ghz intel core 2 with 4GB ram is just about giving up the ghost. Its quite tatty, the screen bezel is taped on and the trackpad is duff. Keyboard keeps playing up and 'not working at all'. If I sell it on a generic auction website as faulty/for spares repair or refurbishment, what sort of price should I look for? This was bought new by my parents in 2006 and has served me very well with little or no problems ever since.

I want to get as much as possible for it, as my new laptop is probably about the same price as a stately home in a 3rd world country.

Any suggestions would be appreciated. Thanks for all of your help Macforum-ers!