I have a MacBook 1.83ghz dual core 1 gb ram. I think the extras you get with Mac are well worth the extra cost. Also, I paid 180 for the 3 year warranty and it's already paid for itself. Because I haul it to class all the time the cable started to fray and I got my free replacement the next day. I was also having a little problem with the screen, so they airmailed me a box with tape, padding and a airmail label and they had it fixed within 1 day. The whole thing took 3 days. Not only did they fix my screen but they noticed my dvd drive was having troubles taking dvds and replaced it. they noticed I had put a hairline crack in the palmrest and replaced the whole bottom case and replaced my wearing trackpad. I didn't mention any of that to them they just did it. Not to mention that iLife package and all the other nice software they package in. 10.5 is going to own.
Also, Shift, and anyone else that thinks you can't do as much with your mac as you can with windows, I felt the same way at first. Things are just located differently but I've also found that if I can't do something I can bring up the Unix terminal and do it manually. It's a matter of changing the way you think.