Demand for homes was up and down on the Big Island and Kauai last month, but buyers generally acquired more expensive properties and pushed median sale prices higher, especially for one piece of the market where the increase was dramatic.

Data from Hawaii Island Realtors and the Kauai Board of Realtors released Monday by Hawaii Information Service showed mostly strong gains in median prices on the two neighbor islands despite choppy sale volume.

The biggest gain occurred for the median price of condominiums sold on Kauai. This figure spiked 62.5 percent to $390,000 in September from $240,000 in the same month last year.

The spike was produced largely from fewer sales at the low end of the market. For instance, the Kawaihau region had two sales for a median $652,500 last month compared with nine sales for a median $225,000 a year earlier. In Lihue there were seven sales for a median $299,000 last month compared with eight sales for a median $143,250 a year earlier.

Such dramatic changes aren’t unusual because a relatively small number of sales are involved and can easily drive swings in the median price, which is the point at which half the sales are at a higher price and half at a lower price.

Overall there were 27 condo sales on Kauai in September, up from 25 a year earlier.

The median price for single-family houses sold on Kauai rose about 5 percent to $550,000 on 35 sales in September from $522,500 on 40 sales a year earlier.

On Hawaii island, single-family houses sold for a median $367,500 last month, up nearly 11 percent from $331,500 a year earlier. The number of sales rose 4 percent to 148 from 142 in the same period.

Condominiums on the Big Island sold for a median $375,000 last month, up 18 percent from $318,000 a year earlier. The number of sales fell 11 percent to 49 from 55.