no surprises come to mind for me.
you'll need money for..
- transportation (T, taxis, and perhaps an unexpected trip home)
- fun/recreation (dining out, movies, theaters, concerts, museums, clubbing, parties, whatever you like to do..)
- and maybe clothes (especially if you don't own any winter clothes and would like to buy them in boston when it gets cold)
that's probably not what you're looking for, but yeah.. i don't think there were any surprise fees charged directly by BU.