It's currently down, but if you go to http://parts.nissanusa.com" onclick="window.open(this.href);return false; you get links to various area dealers (who set the price) when you choose a part or accessory. When you click on each dealer it will give you the price. Unfortunately you do not see the price until you click on the dealer link.
Note that shipping is not included in the quote but provided when you go to checkout, so keep that in mind. Some, but not all, dealers will honor the web price if you go there and pick up the item yourself.
Unfortunately you're probably not going to find that papier-mâché cargo cover for that much cheaper than MSRP unless it's used or a non-factory accessory.