Residential sales on Hawaii island and Kauai rose in May, though home prices varied, a report released Monday showed.

Hawaii Information Service reported a 14.8 percent boost in the number of single-family homes sold on Hawaii island to 147 from 128 a year earlier, but a 10.6 percent drop in the median sales price to $237,000 from $265,000 in the same period. Condominium sales on the island also rose 10.9 percent to 61 from 55 the same month last year, while the median sales price plunged 34.7 percent to $199,950 from $306,250 the year earlier.

"We’re experiencing the impact of value sales, which are the foreclosure and short-sale products," said Julie Hugo, president of the Hawaii Island Board of Realtors. "They’re typically very price-driven — every 30 days there’s a price reduction on those."

Foreclosure and short-sale products — properties where a lender approves a sales price that is less than what is owed — will affect the market for at least the next two years, Hugo said. "There are distressed properties that are in the process of foreclosure. It’ll take some time for them to go through the entire process and then be listed for sale once they’re foreclosed."

Meanwhile, Kauai home sales climbed 3.7 percent to 28 from 27 in the year-earlier period, while the median price jumped to $445,000, up 8.5 percent from $410,000. Garden Isle condominium sales soared 83.3 percent — the largest increase during the month — to 33 from 18. The median sales price rose by the same amount — 83.3 percent — to $330,000 from $180,000.

The relatively small sales volumes in the neighbor island housing markets mean median prices might be affected more by the mix of homes sold as opposed to changes in property value.

There were a large number of discounted hotel and condominium conversion short sales and foreclosures, which bumped up the number of sales, though the median price was affected by a few more high-priced condos that sold, said Mike Olsen, president of Kauai Board of Realtors.

"I would’ve expected the median sales price to go down," Olsen said. "We’re still in that stage where people are looking for and anticipating upcoming foreclosures. We’re seeing capable buyers with large cash reserves holding off because they think there are still going to be better deals down the line."