Unless you specifically need that spec and/or new steel, check local scrap yards. Some (not many anymore) will allow you to browse and help you pull things out of the pile.
I just got about a 3.5' long piece of 3 or 4" angle iron 1/4" thick for $7 a couple weeks ago at a local car scrap yard for a project. It'll need cleaning up, of course, but the price was right for me.
They also had bent sheets, discards, old steel rack support legs that could be repurposed, gotta use the imagination.
But that's only if you don't need the spec like I mentioned.
Good luck in your search.