Difference between rent and mortgage: 209.8% Rents in the home of 7,900-student Princeton University average $2,056 a month -- more than double the $980 monthly mortgage bill on a typical home in the area. Besides hosting a world-famous school, Princeton serves as headquarters for Berlitz, the Educational Testing Service and other large local employers. Bristol-Myers Squibb ( BMY), Dow Jones and other big firms also have significant operations in the area. Additionally, the 60,000-population community is just 10 miles from the New Jersey state capital of Trenton, as well as roughly 45 miles from Philadelphia and New York City. All of this has given Princeton a relatively stable housing market. Median asking prices on Realtor.com rose 0.03% for the Princeton/Trenton metro area in the 12 months ended July 31, to reach $265,000.