The federal first home-buyer’s credit appeared to pay off on Martha’s Vineyard, where October sales of existing homes were up on the same month last year.

A surge in home sales nationwide was reflected in Dukes County — the six Island towns posted 25 sales in October this year, compared to 17 last year, according to figures provided by the Warren Group. Those 25 are a big chunk of the 111 single-family home sales so far this year; by this time last year, the Island had recorded 145 sales.

With smaller numbers, Island trends are harder to evidence. But realtors across the country attributed the October gains to the popularity of a government-financed credit of up to $8,000 for first-time home buyers. The credit was originally set to end this week, possibly pushing buyers to get in before it expired.

However, Congress renewed the credit earlier this month; to qualify, buyers must sign a purchase agreement by April 30.

Lower prices also may be playing a part. In Tisbury, where sales are fairly constant with last year, median prices have dropped substantially. Year-to-date sales in Tisbury are 28, compared to 32 last year, but the prices are off more than 70 per cent — from a median of $1.4 million in 2008 to $430,000 in 2009.

In both years Tisbury had four October sales, but median price was 19 per cent lower this year.

In Oak Bluffs, the number of October sales was up from four in 2008 to seven in 2009 — but prices dropped nearly 18 percent, from a median of $744,125 to $612,500.

For the year so far, Oak Bluffs sales numbers are up from 30 last year to 35, but median prices over that period are down more than 26 per cent.

October sales in Edgartown were steady at seven in both years, and prices were nearly as steady — from a median of $720,000 last year to $750,000 this year. Edgartown has seen a slight drop in sales volumes year to date, from 51 last year to 48 this year, and a slight increase in the median price — from $620,000 last year to $675,000 in 2009.

Chilmark has seen only eight home sales this year, with three of them in October.

At the same time last year, Chilmark had posted 14 sales; that’s a drop in volume of almost 43 per cent. But the prices are up more than 13 per cent for Chilmark sales this year compared to last — from $1.63 million to $1.85 million.

West Tisbury prices are up slightly this year on last, with a year-to-date median price of $732,500 this year compared to $681,250, a rise of more than seven per cent. By the end of October 2008, West Tisbury had seen 16 home sales, none in October; this year the total so far is 14, and four of them came in October.

Aquinnah had no October action either year; its total sales volume January to October was six last year, and so far it’s at two sales this year.

Meanwhile in Gosnold, the seventh town in Dukes County, there were no sales, none this year nor last.