Please note that the links both take you to the queen-size. In order to get to the king-size set, simply click on the option on the product page.
At Macy's, you can find Ralph Lauren pillow 2-packs on sale. Get a set of two standard/queen-size pillows for $14.99 (originally $45) or a set of two king-size pillows for $23.99 (originally $60).
These are medium-density with a cotton cover and polyester fill. No promo codes are needed, and the deal ends July 23.
Make sure to sign up to become a Macy's Star Rewards member so you can get it shipped with a lower $25 threshold. You usually have to spend $49 or more for free shipping, so signing up saves you money.