The northern Long Island state Senate seat held by Republican Carl Marcellino since 1995 was the site of the third-costliest election in the state two years ago, with Marcellino and Democrat Jim Gaughran combing to spend $4.4 million.

And as the two prepare for a rematch of a race that the incumbent won by one point, they appear to be ramping up their spending.

Marcellino's campaign committee has spent $383,000 since mid-July, according to a disclosure report submitted to the state Board of Elections. That's compared to $98,000 he spent in the comparable filing period four years ago, and even more than the $341,000 he spent when former Nassau County Executive Tom Suozzi helped organize an aggressive campaign against Marcellino in 2004.

Gaughran has spent $427,000 in the past couple of months. Two years ago, he spent $118,000 in this filing period.

Both candidates were boosted by transfers from their parties' centralized accounts. Marcellino received $318,000 from the Senate Republican Campaign Committee, and Gaughran got $191,000 from the Democratic Senate Campaign Committee.

Gaughran has raised more money as of late, receiving $184,000 in contributions to Marcellino's $117,000.

If the race again rises to the top tier of the state's most expensive, much of the spending will likely come from independent expenditure committees over the next few weeks. It has already begun to attract funding from those groups: The New York State United Teachers' super PAC reported spending $79,000 helping Gaughran last week, and a group that has received most of its funding from the Communications Workers of America has spent $75,000 on digital ads targeting Marcellino.