Have you seen how much Apple charge for hard drive upgrades? Have have to pay £80 extra on an Macbook to get a 500GB disk compared with a 250. Not to mention having to pay about twice what RAM is worth. Apple's computer business model works off doing simple stuff for you and charging you a lot for the privilege. They don't want people upgrading HDD's because they could be doing that for you and charging you a huge sum for it.