Costco overstock means items which are last year's fashions, styles which are now discontinued, even items which might have some slight imperfections. For whatever reason, Costco didn't sell them, but for you as a consumer or a retailer - that's great news because Costco overstock can save you huge amounts of money!
One of the best things about Costco overstock is that no one will know that you bought your stuff at discount - all that matters is that you are getting the best price for the goods that you want!

The place to start your search for this bargain hunter's paradise is to try and find a Costco return/overstock outlet. These places are usually wholesale suppliers who have been brought in by Costco to shift merchandise that they can't themselves. There's usually nothing wrong with the merchandise, Costco just need to clear space to sell newer products, and because space costs them money, they get rid of their old stock at massively reduced prices.