A small group of American universities is crossing a threshold that once seemed absurd: $100,000 for a single year as an undergraduate. At least 16 institutions are now approaching or exceeding that figure when tuition, fees, housing and other miscellaneous costs are combined, according to a recent analysis by New York Magazine. The list — corroborated by data obtained by CNBC — is dominated by elite, high-demand schools, including the University of Chicago, Georgetown University and Wesleyan University.