I was browsing around and found this site.
https://www.storesupply.com/pc-13501-518-3-w-x-3-h-black-mini-grid-unit-with-back-30201.aspx
it seems like a better deal than buying two of the 4 cube sets.
https://www.storesupply.com/pc-13501-518-3-w-x-3-h-black-mini-grid-unit-with-back-30201.aspx
it seems like a better deal than buying two of the 4 cube sets.