Those are some nice shelves.
I know from experience that they are expensive as well. We have about 10 of them that were ordered at work. We use them to move, haul, and store tons of computer equipment. They hold a great deal of weight as we load them with 21" CRT monitors and heavy tower systems... they don't budge. When putting them together I found it hard to believe that those small black plastic sleeves would support so much.
We've even loaded them up with PC's, shrink wrapped the whole rack, and loaded them onto a Ryder truck when bringing equipment back to town after Hurricane Katrina. Talk about a life saver but man I don't want to have to do that over again
