In a way it almost adds a slight (and I do mean slight) levelling up edge? Players who wont bother collecting enough sands will find the dungeon that bit harder than those who went out searching. Plus, if your not meant to spend much time in the Dungeons, how are they going to stretch it out? More dungeons? Or more side-quests?

I personally didn't mind the save feature in MM but of course prefer when you can save anytime yet it remains to be seen.