Amazon has a 6-Pack 50-Piece (300-piece total) Mentos Pure Fresh Sugar-Free Chewing Gum with Green Tea Extract, Curvy Big Bottle (Spearmint) for $9.36 with free shipping on $25+ or with Prime (extra 5% off with 5 items S&S order).

Has a high xylitol content, which helps reduce tooth decay, and contains no sugar.