Spanx cuts up to 50% offsale items. (Click through the "Sale" tab.) Even better, take an extra 25% off via coupon code "JULY25". Plus, the same coupon bags free shipping. Coupon expires July 31. Some best bets, with prices after discount:
Frederick's of Hollywood offers its Frederick's of Hollywood Women's Unlined Essential Bra in Nude, Black, or White for $13.99 with free shipping. That's $15 off list and tied with our May mention as the lowest total price we could find for this bra. It's available in select sizes 32B through 36A, though not all size/color combinations.
GearXS offers the Hanes Women's Hi-Cut Panties 14-Pack in White for $19.99. Coupon code "GXS-30" cuts it to $13.99. With free shipping, that's $1 per pair and $18 under the lowest total price we could find for a 12-pack elsewhere. They're available in sizes 6 to 10.