In the chart, the red line shows the mortgage payment you’d have to make if you took out a standard 30-year mortgage for the median asking sales price for vacant sale units. In reality, your mortgage payment would be lower, since this doesn’t take into account any downpayment. But in any case, thanks to ludicrously low mortgage rates below 9%, that number is now lower than the median national rental price. This is the first time that’s happened since 1988, and probably for quite some time before that, too.
Now before you go buy a house, do make sure to check against local conditions. My understanding is that this math doesn't necessarily add up in Hawaii, the New York area, or the vicinity of San Francisco. But if you've never owned a home you should take a hard look at the local math. In fact if you're daring and you already own a home, you should think about buying another one and renting it out. Personally, I don't want the hassle of being someone's landlord, but your return on investment at this point is way better than anything you'll get in a bond market.