Check to see if your school can use School Outfitters. You can get the Wenger move and store carts at a discounted rate through this company.
I have Wenger student music chairs, but the Wenger chair racks are very pricey. I found a similar rack, but I'm not sure if it will fit the Wenger chairs. Does anyone have experience with this? Here's the link to the chair rack that I found.