I am thinking about buying used an 20" imac 2.4 core 2 duo (early 2008) from a man on craigslist. He is asking $800, but is offering it with some valuable software preinstalled, so it caught my eye. Aside from all of the things to be aware of about purchasing anything on craigslist, I want to know if this particular model is known to have any failures or any issues I should be aware of. I know certain models of imacs should be avoided and want to be sure this is not one of them. Thanks a lot.