Absolute Ring Event

Why even complicate it by doing it all in one NPC interaction.
Days 1-12, ring +10 or less: Upgrade ring.
Day 12-60: Gaga makes it tradeable if you ask. (event runs until the end of August)


Giving you a single day to make it tradeable is unnecessary; letting you turn your untradeable item tradeable isn't abusable.

If you ask "make my ring tradeable" on day 45, do you mean ring I or ring II?

I think the simplest way would be to keep all rings untradeable until the "reward phase" (August 19 - Sep 2). When you talk to Gaga then, your rings are either consumed to make the Absolute Ring, or made tradeable with whatever stats you managed to get on them. That way these abuse plans people are hatching (of giving gaga +1 rings instead of the +10 or +11) would also be nipped in the bud.