I was totally surprised at the quality. You should go during sunset hours. My friend who's been to Egypt said it was better than even Egypt. Anyways, I think it is absolutely worth it to visit Tottori just for this place.

About:

If you visit Tottori Sand Dunes, expect very windy, loose sand and bring sun protection, plenty of water and closed shoes or sand socks since walking is harder than it looks. Go at sunrise or sunset for cooler temperatures and the best photos, and dress in layers because the wind can be chilly even on warm days. You can rent sandboards or take a short camel ride near the entrance, and there are restrooms, a small visitor center and cafés by the parking area; it is reachable by bus from Tottori Station in about 20 minutes or by car. Note the dunes themselves are not wheelchair friendly, though an observation deck near the parking lot offers accessible views.