I usually have things I need to bring back and forth from home to school. When my schedule was tighter, I would bring home art to photograph for Artsonia. Now it’s usually towels and paint t-shirts to wash and occasionally supplies or donation.
I went through three fold up plastic rolling carts (at $25 each) before I landed on this solution.
The cart is a “Magna-cart”. It was about $30 at Home Depot and holds 150 pounds. The plastic bins were purchased from Craigslist and are “milk crates” that are really durable (I am not sure how much those were). The bottom one I strapped to the cart with zip ties. It doesn’t fold flat like the file carts but I am okay with that since I have used this for 5 years now and it is expandable when I need to bring more supplies somewhere.
When I have taught at locations such as the Mega Conference or a scout workshop or a paint and sip class, I can stack several crates and use a bungee cord to hold the bins to the dolly.