Tips for tower events are here.
Startbonus: 125 coins
Collections: 600 coins every 8 hours (5400) = Total: 5525 coins.
The total does not include coins from quests or Dragon TV.
For collecting times check this.
Giant Wings -R- #239: 3 pieces.
Blue Fire -VR- #207: 4 pieces.
Fire&Ice -E- #766: 4 pieces.
Darkjester -L- #866: 6 pieces.
Freeze Flare -L- #1424: at the top.
Rumors say that there might be 1000 gems in one of the ice chests.
For a better resolution click this link: https://rb.gy/nggdua