Home prices in the Tampa Bay area fell to a 10-year low in August, according to a report Friday from Ybor City consultancy Home Encounter.

Home Encounter estimates that area sales prices averaged $89 per square foot last month, down 7 percent from a year ago and down 4 percent from July. Home prices and total home sales fell substantially in July following the expiration of homebuyer tax credits.

Home Encounter president Peter Murphy said there was no doubt the tax credit pushed prices higher, at least temporarily.

"Sellers asked a premium for their homes, which buyers were willing to pay to take advantage of the tax credit," he said.

Four months later, he said, prices have dropped by an average of $13,000, indicating tax credit-buyers overpaid.

The monthly report - which is drawn from Multiple Listing Service information on home closings in Hillsborough, Pinellas, Pasco and Polk counties - is a precursor to more extensive sales data from the National Association of Realtors. The Realtors' August report, which includes numbers for all of Florida, should be released Sept. 23.