Anyone Have a Used Ruida Controller for Sale?

I know I could just buy a cheap and new GRBL controller for my experiment, but I like the simplicity of the Ruida DSP. I deal with enough complexity with a Mach 3 motion controller.

I am working on building a Ruida controlled plasma CNC cutter. The concept is pretty simple. Leverage my existing CNC mill’s power supply, stepper drivers and steppers, slap in a Ruida DSP, and drive the plasma cutter (which is just basic on / off across two pins on the machine) from the CN5 pin 2 output (L-ON1) of the Ruida controller. I really think it will be this simple to make a LightBurn enabled CNC plasma cutter.

So I went to eBay, Amazon, and Ali Express to browse for a basic Ruida DSP and thought maybe to check here before buying a new one. Maybe I save some money for something that may end up not working anyway.