Amazon America currently has LEGO Monster Fighters 9467 Ghost Train on sale for $57.08 (reg.$79.99). Savings work out to be 29% off. Free shipping and no tax for most states.
In addition, they also have LEGO Star Wars Elite Clone Troopers vs Commando Droids for $9.74 (reg.$12.99) which works out to be 25% off. LEGO Chima Chi Battles is also down to $14.97 (reg.$19.99) which also works out to be 25% off. More of their hottest LEGO deals can be found here.