2,750 g
This item page for Reverberation reflects public Arena Mayhem data for patch 26.19.
Unique - Reverberate:
After 2 seconds from the start of the combat phase in each round, gain 5 bonus health per 1% bonus attack speed.
Unique - Resonate:
Basic attacks on-hit deal 10 (+ 2% of your bonus health) bonus magic damage.
Immobilizing an enemy champion using Puppeteer's Pull Their Strings does not grant stacks of Reverberation.(bug)