I DIY'ed mine
I Picked up 4 dolly wheels. All pivot, with brakes, to allow me to manouver the thing out of the darkroom from time to time if demonstration sink work to a group is needed. That was about $38 as I recall.
Then melamime coated MDF, 3/4"x4'x8' at home depot, and had them cut the major sizes I wanted for the top and two sides. about $60 or so I think. Most of the money went on plumbing modofiactions, so the limber costs were not as memorable.
The wheels are lag screwed to a 2x4" frame that is well screwed to the MDF sides. The cart is open to the front, and only has a partial rear to provide bracing. There is a shelf to hold bits; it is high enough to not interfere with overflow tubes that drape into jugs that sit on the bottom of the cart.
Solution jugs for active chemistry also sit on the lower level of the cart
I made the top sized to fit the fujimoto cp31 and wash dry unit I rehabbed. The sides are set in from the top, and this allows me to hang the racks on the sides of the cabinet on pins set into the cabinet side when I want to keep them out of the tanks. I usually pull and rinse them in the adjacent sink before doing this. It gives me a place to put them that does not otherwise clutter the darkroom. Sometimes I will do this and lay saran wrap over the tanks if I am going to be back to them in under a day and the chem is getting old; otherwise I drain and rinse at the end of every session.