It is also worthy to note that the box protectors being sold in that particular eBay auction are of an inert plastic (polypropylene) and won't damage the contents of the box over time. The box protectors sold at Clearbags are made of PVC and will turn your boxes a shade of green in a few years.
Edit: In case you're wondering, I bought 275 box protectors from justabum (cost me $150 shipped), and they do their job very well. And if you need help finding him, he's a registered member at NintendoAge
.