So: $939 works out to a little more than $4,000 a month before taxes. How much of that would you need to spend if you bought the average Baltimore-area home in March, priced at just under $307,000?

About 46 percent. (It's over 50 percent for the average home in Maryland.)

That's assuming a 6.5 percent interest rate on your mortgage and a 5 percent down payment. And the figure doesn't include escrow -- the annual property taxes and insurance.

You'll hear different advice about how much of your before-tax income to spend on housing, whether purchase or rental, but the definition of "affordable" is usually in the neighborhood of 28 to 30 percent a month.

At least a couple working in average Maryland jobs could have swung a purchase of that average March home.