I too had trouble finding the Crown Prince. I decided to head to the /loc given for the secret entrance and I was a bit South of the outpost when I got a popup saying I saw the Crown Prince and I should follow him. Sorry I didn't get a loc, but decided following was more important.
I cannot find this Crown Prince where they say he spawns. He does not appear in the onlyu sheerva outpost I've found in the NE corner of silvermine mts at the loc given of 54200,1000 Need some help to continue this epic quest