The supply of houses for sale in the Phoenix market increased 24% over the past three months as investor interest in the market waned, according to the W. P. Carey School of Business at Arizona State University.

With bargains becoming tougher to find and other state’s housing market attracting potential homebuyers, investor interest is trending downward, the report said. Still, 30.3% of all homes purchased in Maricopa County, the county seat of Phoenix, were purchased by investors in September, up from 27.5% in the year-ago period, but down from August numbers, according to the report.

“This market is relatively well behaved,” said Mike Orr, author of the report, in a statement. “Investors are risking their own money, rather than borrowed funds, so risk is being more carefully managed than in the previous boom.” 

Home prices stayed steady at $150,000 in September from August, but were 27% higher than September 2011. Home prices are expected to start rising again during the fall.

New-home sales and normal resales are also on the rise. The number of single-family home resales increased 76% from 2011. Realtors also noted that the average price per square foot increased 23.3% from a year prior.

Foreclosures continue to see a decline in the market. Foreclosure starts decreased by 18% in September from August. Completed foreclosures also dropped 31%.

“Lenders are aware of how much prices have increased for the post-foreclosure homes they have sold recently, so they have been requiring higher prices for short sales before they will agree to them,” Orr said.