Ring of Heighten Spell

[Josephgene]

I want to give a treasure to my heroes.

I want to create a ring that when used to "craft magic item" or "craft wonderous item" it enhances the spell by two levels.

For example:
They take the ring to an NPC who crafts it into a ring of cats grace +4 dex 1min/level.

The ring itself has magical properties (history of "magic metal" in our world) that allows whatever spell it is enchanted with to increase the spell by two levels.

So the spell of cats grace on it will be as if a level 3 bard casted it. +4 dex for 3minutes

Before i make it a homebrew rule, wondering if there is a rule?

Thoughts? Questions? Comments?
all welcomed.
-Joe

[Tallkid]

I think that would simply be a wondrous item or ring created with a higher caster lvl. Nothing special required just an appropriate caster lvl and some extra gp.

[Josephgene]

So in order to create I would charge for level 1 but the wondrous item will transform the level 1 spell to a level 3