Well,
If you're just thinking about getting a Mac and you're not sure you'll like it, be sure to choose wisely. But if you're set on a Mac here is my advice.
The PowerBook seems to be your best option if you intend to use it as a your primary, feel you need the extra power (IE: video, hdd speed, processor). Many people will tell you to wait until the Mac/Intel machines come out, but if you need one before they do, then you must buy the current machines--which by no means is a bad thing.
If you do decide that a PowerBook is the best choice then you have two options. Used and new. New will certainly run you upwards towards $2k. Used--I've seen the current PBooks (1.67) go for as low as $1500 in some parts for the 15".
Do you need 17" Do you need that much screen? The reason I ask is that the verdict is out on whether or not the 17" is as portable as some would want it to be. Some will say yes, others will say no. I see many auctions online going for 17" because they say they got the bug saw the 17" and all it's wonder and bought, now they want a 15" so they can lug it to class.
I bought a 15", had more than enough for a 17". I nearly bought the 17" when I saw it, but I remembered that while I am out I want to carry that, a binder and some books. While at home it's plugged into a LCD. So the 17" would not be used as much and I didn't feel the need for the extra weight. The 15" offered just as much power. the 12" was out of the question due to the fact that by the time I put a superdrive into it and upgraded the video as much as possible (if possible) I could have bought a lower end 15".
Think of it this way. When you're in your dorm or where ever you live, will you use an external display? If not, maybe the 17" is for you. I can't honestly think that an EA major wouldn't have an external display, but that is just me.
My solid advice to you if it were me is the 15" loaded up with a larger hard drive and BTO 1 gig ram stick (leave the other slot open) and then an external display (dell 20" wide, 24" wide or ACD 20", 23", 30") whatever you can or want to afford. The second slot of ram should be filled with another gig from Newegg.com or Crucial. I would buy newegg. I bought another stick of Kingston and it works so great. The things I upgrade with the BTO machines are hard drives because buying and replacing it would be tough, but not impossible, and video of course.
I couldn't be happier with my decision to go with the 15" I would have been sad with the 12" because I do happen to run around on vacations and such with the machine so I am looking at photos on my screen. School would have been fine with the 12", but I knew the notebook would serve a higher purpose.