Let the hive mind of Engadget get that for you.
"I'm heading to university next year, and I've purchased a MacBook. I'm also taking my four year old desktop, just in case I'm left with no computers when the MacBook is being repaired or whatnot. With only two USB ports on a MacBook, I want a Bluetooth mouse. Budget is about $100, and of course, it needs OS X support. Thanks for the help!"
Seems like good deal for me.
As a 3 series owner I have not forgotten that BMW charges $1000 to "upgrade" to leather from vinyl seats in a $40K+ car.