Low-cost carrier Spirit Airlines just announced a new version of its Big 'S' Sale with prices starting at $19 each-way for domestic and Caribbean travel. Though serious restrictions apply, and the lowest fares are available for midweek winter travel, Smarter Travel investigated and still found savings of more than $300.

Fly to Mexico on American from $198 R/T. Destinations include Cozumel, Cancun, Los Cabos, Monterrey, Puerto Vallarta and Mexico City. Valid through March 31, book by December 15. This sale is hot!

Via Smarter Travel