Personally, I'm a huge fan of Kennedy boxes and cabinets. I used them throughout my working life and still enjoy them.
I also have a Kennedy cantilever box that I paid 9$ for, about 30 years ago. It's great for storing taps, dies, mill bits & drill bits. I also built a riser to place it on my Versa-cart.
Unfortunately, used Kennedy boxes and cabinets are undervalued. It's funny that I can sell a modern, low quality, Craftsman box/cabinet a lot faster than a Kennedy/cabinet.
As far as selling a Kennedy cantilever box: In my neck of the woods, I'd probably stick it on CL for 50$/OBO and see what happens. Depending on interest, you can always reduce the price.