The Ring of Spell Storing allows you to store any spell by casting it into the ring as the spell would normally be cast, presumably expending any material components required at this time as general rules.
A spellcaster can cast any spells into the ring, so long as the total spell levels do not add up to more than 5.
It is also clear that no material components are expended when casting spells from the ring.
The user need not provide any material components or focus to cast the spell...
However, some spells such as Restoration require a variable material component cost depending on decisions made when the spell is cast.
Components V, S, M (diamond dust worth 100 gp or 1,000 gp, see text)
This spell functions like lesser restoration, except that it also dispels temporary negative levels or one permanent negative level. If this spell is used to dispel a permanent negative level, it has a material component of diamond dust worth 1,000 gp.
What price diamond dust is used to store and cast Restoration in the ring and when is it expended?
Can you choose to expend the 1000gp diamond dust and then not dispel a permanent negative level?