Trying to decide whether it makes sense to buy a home? Check out a new online calculator.

But be mindful: It's not a typical Web calculator from a real estate company or a lender. Instead it's from the Center for Economic and Policy Research, a bearish Washington think tank that's been predicting a housing price collapse for more than a year.

The center says its Housing Cost Calculator "takes into account the unprecedented rise in house prices since 1997, as well as current house and rental costs for 378 metropolitan areas." The Washington region is among them.

The calculator lets potential homeowners see how much a property will cost over time and compares the amount of additional cash available to a renter with the amount available to a home buyer who sells at a specified time in the future.

Dean Baker, the group's economist and co-director, has been raising red flags for months about the potential of a bubble in areas with high speculative buying.

While Baker has conceded that housing markets "clearly are local" and some could escape a escape a major downturn, his group constantly warns that hot markets like Washington's are seeing aggressive speculative buying and "vastly inflated" prices.

-- Sandra Fleishman