The Chronicle Almanac from 2008-2009 reported the average cost of “books and supplies” at a 4-year private college as $1054. If accurate, that is still pretty small – less than 3% of total costs (I can’t tell if the overall annual pricetag of $37K for the average 4yr private institution accounts for discounting – either way it’s not much by comparison).
I agree that this seems an easier place to save in the short run. It will require many curricular adjustments, but it culturally in line with the desire for more openness in scholarly communications and elsewhere.