workalicious reader nothingfuture posted a comment about this great shelving system from Ikea:
IKEA makes a shelving line called "Broder" that is nicely priced, flexible in setup, and even has the same industrial finish. It's not perfect, but for very few dollars I now have an excellent desk.
Indeed this very affordable shelf system from Ikea can be the basis for your vertical desk set up.
Its a conventional slotted shelf standard system, but it comes in freestanding or wall mounted configurations, and Ikea has a great range of accessories,many which you can hang on this slotted back panel:
Desk tops are available in steel, or wood.
Similar to the E-Z Shelving system brackets the triangular shape will interfere with your ability to roll your mobile desk under the desktop shelf. I think with a little modification this can easily be overcome.
So there it is, by far the least expensive path to a shelf system for your vertical desk.