I am considering selling a two year old, 2.2 GHz (Santa Rosa) Macbook Pro. This model has a 120 gb hard drive, 2 gb of ram, mac os x tiger, and 128 MB nVidia 8600M and matte LED backlit screen. What is a good price to sell this laptop for? Are there any upgrades I can do to increase the retail value (more than the amount of the upgrade)? Any help would be greatly appreciated.