Used items can be a huge savings off the regular price. I never post a warehouse deal for less than 50% off. Usually they are returns. Even if they are in "used acceptable" condition they are usually like new but have beat up or no original packaging. If it is not in acceptable condition when you receive it, you can return it for free, just like any amazon item, as long as it is shipped and sold by amazon warehouse.
Click the amazon link in the post and look for "New and Used (##) from $##" and click that link. (If you don't see that link, the used items are probably sold out). When you click the link, the list of available new and used items will slide out (at least on desktop browsers - the app may look different). You can review the condition, and add to cart from there.
Note warehouse deals are usually very limited in quantity, one or two is average, so if you want an item buy it right away.