I was looking at the black plastic ones they have at Walmart. They aren't the cheap ones and are pretty thick but I am not sure if they would hold weight as well so just going with the metal ones. I am in the process of finishing up my new grow areas and think maybe even the ones on wheels if I needed to roll them. Like you said, very handy, cheap and totally need more lol.Yes it has been very handy and it was cheap. I need more.
LOL, I still have my old grow box. This was built when I was like 16 in high school 30+ years ago. This is an older picture when I finally extended into my closet. Nice little set up though. Simple, easy and does what it's intended to do.