does any one know the cost of a digital display or where I could find a used one.
Well Bernie, I can't help you regarding a used one. A new one is listed as $995.99. And you know by now that it's not your Mode Switch.
Troubleshooting wise, for intermittent operation of the display, the manual specifically calls out checks for power and ground. Keeping in mind I'm looking at a 2011 wiring diagram here, but if it was an intermittent power problem, perhaps you'd have more things not working than just the display. But you might want to ensure you don't have any intermittent connections on your fuses and Main Relay #2. On this diagram, power comes in on connector pin #8 to the display.
However, it appears that there is a dedicated ground from the display using pin 11 of the plug in connector, and going to a ground connection on the frame. Probably that one in front of the motor under the ECM and resonator. There's about a dozen wires all on that one bolt. Might want to clean and check that.
Edit: And now that you have it apart of course, you can inspect the pins in the connector, hose it down with electronic contact cleaner, plug it back in a see what happens. And according to the manual, you will need BUDS if you replace the cluster, in order to match the cluster to the ECM that's already installed in the machine. The engine may not start, otherwise. Also, the rear suspension sensor will need reset. It's not just a plug and play swap.
Wish I could help further. Good luck with it.