Portland-area’s May home sales fell to that month’s lowest level in 15 years as the pool of discounted foreclosures dried up, but the median sales prices are not shrinking at the rate of most other western markets. According to a report from MDA DataQuick, a San Diego-based firm that watches real estate data across the nation, foreclosure resales in the Portland-Vancouver-Beaverton metro area jumped to 17.2% of all resales. In most western markets, foreclosed homes make up half of all resales. For May, 2,465 new and resale homes changed hands, an increase of 4.6% from April, but a 22.2% drop from a year ago. It was the lowest performing May since 1994. For 39 consecutive months, sales have dropped on a year-to-year basis, where the total is compared to the same month from last year. However, the regional median sales price held steady, slipping only 0.4% from April to $240,000. The average price did drop 12.7% from a year earlier and 16.9% from its $288,858 peak in August 2007. By comparison, the median price has dropped from a year ago in Phoenix by 38.4% and by 43.7% in Las Vegas. In another sign that first-time buyers are migrating to the area in place of bargain-hunters, government-insured FHA loans were used in 35.8% of transactions. Write to Jon Prior.