So much for being the most expensive Super Bowl ever.

With ticket prices in a freefall, seats for Sunday’s MetLife Stadium matchup between the Seattle Seahawks and Denver Broncos could end up being the least expensive for a Super Bowl since the post-9/11 game of 2002.

After hitting record highs last week, ticket prices took a nose dive over the weekend, with the cheapest prices plummeting nearly 50 percent, to a low of $1,150 from about $2,200 at 9 a.m. on Jan. 19.

While the cold weather had been a concern, that’s now been factored into prices and isn’t expected to have much of an effect going forward, unless there is a snowstorm, market watchers said.

Instead, limited travel demand by fans of the two Western teams, a glut of available tickets and sluggish interest in the New York metropolitan area are contributing to the tailspin.

More than 18,000 tickets remained available on the secondary market Monday.

“Everyone had this notion at the beginning of the process that this would be a hot ticket and prices would match everything else in New York,” said Chris Matcovich, of Tiqiq.com, a secondary ticket marketer.

“The fact of the matter is that is not the case, and it doesn’t look like that will be the case a week out.”

The combined 4,600 miles for both fan bases to travel is “a bit tough,” Matcovich, said.

He said ticket prices may show “a slight uptick” as the week progresses, but they’ll likely come back down by the weekend.

“Brokers this week are praying that locals bail them out and start buying,” he said.

Connor Gregoire, of Seatgeek.com, said the market “is in a tailspin,” with prices spiraling “at a record rate [and] likely to be dragged down further.”

The average price paid for a ticket plunged 40 percent over the weekend, to as low $2,056, from $3,439 in the first 24 hours after Seattle and Denver won their games last week, he said.

The average price moved up slightly by Monday, to $2,862.

“There’s effectively no way that this game will be the most expensive Super Bowl ever when it’s all said and done,” Gregoire said.

“It looks increasingly that this year’s Super Bowl will be the least expensive since XXXVI in 2002 [when] tickets were selling far under face value on game day.”

Stacked up against all recent Super Bowls, this past weekend’s average price ranks as the cheapest paid for a Super Bowl ticket on the weekend before the big game since 2011, Gregoire said.

The average price for a weekend-before-the-game ticket in 2013 was $2,512. It was $3,127 in 2012 and $3,513 in 2011.

On Monday, the lowest-price ticket in the mezzanine section was $1,781, off nearly 40 percent from the prior week, and lower-level tickets could be had for $1,870, also off 40 percent, Matcovich noted.

Meanwhile, prices for seats with access to heat — private suites or seats located by a warming concourse — are “holding steady,” said Gregoire, with the average sales price between $6,000 and $7,000.

“Realistically, if sales don’t start to pick up in the next few days, this weekend will be a buyer’s paradise,” Matcovich said.