According to this special sale page on Amazon, you can save an additional 25% off select LEGO sets. The instructions say to just add qualifying items to your cart and the discount will be reflected at checkout. Well, all I can say is that the instructions LIE. Well, maybe they do. I got all the way to the end with no discount. Their codebase may not have been updated quite yet, but I would keep an eye out to see when the discount triggers. Some notable sets include LEGO Star Wars 10198 Tantive IV and LEGO Creator 10197 Fire Brigade, both of which are already seeing a price drop down to $139.99, a 7% discount, before the 25% kicks in. Good luck!
Thanks to yakkotank for the tip.