Sales of existing homes on the Big Island and Kaua'i last month were mostly up, but median prices were mostly down, according to a report from the Hawaii Information Service.

The biggest increase in sales was for condominiums on Kaua'i, where sales more than doubled to 15 in August from seven in the same month last year.

Six of the eight additional sales occurred in the pricey Hanalei area, which includes Princeville Resort. But the median price for all Kaua'i condo sales was up just 0.3 percent to $300,000 last month from $299,000 a year earlier.

The median price is a point at which half the sales were for more and half for less, so differences in the quality, size and other characteristics of homes sold can easily affect the figure when the sample size is small.

For instance, in the Koloa region that includes the Po'ipu resort area, the median condo price was $170,000 on three sales last month, compared with one sale for $825,000 a year earlier. In Lihu'e, the median was $275,000 on three sales last month, compared with $210,000 on three sales a year ago. In Hanalei, the median was $585,000 on seven sales, down from $731,500 on one sale in the same period.

There were 23 single-family homes sold on Kaua'i last month, down from 27 a year earlier. The median sale price was $471,000, down 11 percent from $530,000 in the same period.

On the Big Island, single-family home sales were up 12 percent to 97 last month from 87 a year earlier. The median price was down 3 percent to $310,000 from $320,000.

Big Island condo sales totaled 37 in August, up from 32 a year earlier. The median price was down 29 percent to $205,000 from $287,000.