That is an excellent price on the Powerbook. If you have a lot of music and large files, get the Powerbook, due to it's larger hard drive and also the Superdrive. If not, save some money (since you are a grad student and your wife is pregnant) and go for the iBook. Personally, I love the 14 inch one for its larger screen, but if you're used to using the 12 inch one, it should be no problem to go with that.