Automatically Send Out of Stock Products to "Sold Items" Cat

[Khorin]

A client of mine is requesting a certain feature Etsy has that automatically sends a sold item to a page that only lists sold items. Here's an example: http://www.etsy.com/shop_sold.php?user_id=5365727

 

What I've done is just create a "Sold Items" category and move out of stock products to that category. I'm also using a contribution that replaces the "Buy Now" and "Add to cart" buttons with a "Sold out" button.

 

It's my understanding that my client wants something automated instead of her manually changing anything.

 

Any help is appreciated! If there are no solutions, I guess she's stuck with what I came up with!