Amazon America currently has LEGO City 7499 Flexible Tracks on sale for $15.98 (reg.$19.99). These rarely get discounted so its not a bad time to pick some up to build up your train tracks! They also got a variety of the latest 2014 LEGO City sets discounted by 20% off including 60057 Camper Van for $15.98 (reg.$19.99) and 60053 Race Car for $7.98 (reg.$9.99). Thanks to forum member grymg for the heads up.
Outside of LEGO City, they also have LEGO Teenage Mutant Ninja Turtles The Shellraiser Street Chase on sale for $44.99 (reg.$59.99). Savings work out to be 25% off.