The wacky world of $2 eats is getting a serious player: Subway.

Wednesday, the nation's largest sandwich chain will announce plans for a $2, six-inch sub sandwich promotion for the month of December. The deal is good only on its popular meatball and cold-cut subs.

In a still-struggling economy, the chain that set the industry standard with $5 foot-long subs is throwing down yet another gauntlet that's certain to raise industry eyebrows and lure deal-seeking customers. Several other major fast food chains also dabbled this year with $2 meals — including Taco Bell, Chipotle and some regional KFCs.