Is there any more important rule in real estate than, "location, location, location"? In case you've been living under a rock, that's the answer to the question, "What are the three most important factors in buying a home?" The basic idea is that it's not the Sub-Zero fridge, the spacious deck, or the fancy faucets that dictate whether a home will hold its value. What matters most is where it's located.

USA Today proves the point yet again today with new findings from a Coldwell Banker survey. The survey looked at similar houses -- all with four bedrooms, 2 1/2 baths, a family room and a two car garage -- and compares how much they cost in 384 markets around the world.

The most affordable place in the U.S. is Minot, North Dakota, where a four-bedroom home lists for $132,000. The least? Beverly Hills, Calif, where the price tag is $1.8 million. Take the trends abroad and you can pay $1.8 million for that kind of house in Milan, Italy, or just $56,500 in Bogota, Columbia. The average sale price in the U.S. is $424,000 (you can parse all the data here).

What good does this information do you? Well, if you just paid $2 million for a split-level in Greenwich, Conn., and are worried you bought at the peak, this data may make you feel better. At least you bought in a premium location that will hopefully hold its value.

Better yet, if you are thinking of trading down, a handy tool at the Coldwell Banker site allows you to crunch this data and see how much a home comparable to your own would cost anywhere else in the country. For example, you can trade in that $2 million Greenwich home for a similar $278,000 house in Amarillo, Texas, should you one day decide to head to cattle country with plenty of free cash in hand.