All Outlet Store items are based on availibility and if we run out before we remove it from the website then we are still out of them. Which is why we don't like people buying and returning them.
Also, it seems I now have to say the following: This Trade Up program is a heck of a deal. You cannot use a discount, promo or coupon code with a Trade Up item. Same with Outlet Store items. If you mix Trade Up and Outlet Store items, and sales or regular priced items, then the discount will be taken on them.