By the time one component needs upgraded, it's pretty likely the whole machine needs upgraded (if you buy a good computer to begin with). This isn't universally true, but it's a pretty good model. I agree that is a definite downside, but that same fact also provides a good aspect of the mac: inherent compatibility.
i agree with this guy
o yeah and i know you can use a regular mouse
but im not going to bring a mouse from my house to school just to do a lame ass project or something
i will never buy an apple computer!
If you ever go into work with graphic or audio editing, I'm nearly positive you will. Like I said, Macs have their purpose. For at least the two things I just listed, they are noticeably superior to the PC.