Tuition at BU for 2012-13 is not $59,100: it's $42,994. The $59,100 figure includes books and supplies ($1000), room and board ($13,190) and $1916 "other" expenses. About 65 percent of students there receive financial aid, and the rough estimate of the 2012-13 net price is around $31,000.
BU's endowment in 2011 was $1.16 billion. On a per capita basis (only counting undergrads), that's around $64,000 per student -- roughly one-twentieth the size of Harvard's per capita endowment.