It would be easy to adjust this simple design for your own needs. Here's a material list for anyone wanting to make this one:
1 3/4" piece of plywood 20x30 inches for the base
1 1/4" piece of plywood 20x30 inches for the top (get a thicker piece if you expect to put heavier items on top.)
6 pieces of 16" 2x4's for the posts
4 swivel wheels each rated for 125 lbs for an expected 500 lb load.
12 #10 1" screw to attach the top piece
12 #10 1 1/2" screws to attach the 2x4's to the base.
All these materials were less than $60 at Lowe's hardware; but could probably be less at discount lumber places or if you have some of these materials on hand.
A lot more time was spent moving things, re-cutting boards to sit on a metal shelving unit so I can use it as another ware cart, and getting more raw materials into plastic, stackable storage bins, and labeling them.
This morning I'll get some studio time and this afternoon I have to get back to Lowe's to return something and buy a new surge protector for my wheel and a new timer for the plant light, followed by a stop at my local butcher/fish monger to buy some fish for dinner
It's going to be in the mid sixties today, the last day for this good weather; and then the temperatures are dropping way down, with a lot of rain in the mix. So,when I get home I'm going to plant some cold tolerant veggies, cook dinner and vegg out for the evening. Hope I can stay awake for the River Dance show on our local PBS station at nine o'clock. It's going to be iffy, for these old bones, after such a busy day.