bret: our series on the housing crisis focuses tonight on the age ol question: should you buy or rent? chief washington correspondent james rosen reports the numbers say one thing. but many people are doing the other. new parents laura and vincent feel like renting the last five years was a big-time waste of money. and are accordingly excited about the home they just agreed to buy in northern virginia. the mortgage rates as they are now, it seems like it s the best time to grab them before they go back up. zillo.com reports rental prices increased in 70% of american cities last year, while home prices increased in only 7% of cities. the wall street journal found that from january 2011 to january of this year, median rents rose 3%. while home prices fell in that same time period by nearly 5%.