I already know how GP works, but I was wondering about the guy who you can buy GP from in the main entrance. I've heard that's there's a random chance he'll appear in the vicinity of the small hut with three windows.

Does he visibly appear, or do you have to run up and inspect the hut every time?

Is he inside the hut or outside of it?

If he's inside, can you enter the hut or do you approach a window?