It has been determined that the CL of the magic item is not the CL used to determine the DC when crafting the item. It is actually determined by the spell(s) that are in the magic item.
In the case of the rings of Spell Storing, they all require the same 4th level spell, Imbue with Spell Ability. Does that mean they all have the same DC when crafting each one? To me, that doesn’t make a lot of sense, especially since the ICL is progressively higher (5th, 9th and 17th).
I’m assuming there is no official ruling on this and would be a GM call. If so, what would you (as a GM) rule this as?
From a practical standpoint, I wouldn't really care. If a level 5 cleric somehow has 100,000 gp lying around, there are much more disruptive things he could do with it than spend it crafting a Ring of Major Spell Storing.
Frankly, I think it would be unlikely to come up in any game I was GMing.
Yes, that’s a good point. If the campaign is being run correctly, no character should have that much cash lying around.
Oh, btw, any crafter (with the correct feat) could make that item, not just a Cleric. :)