Maze explanation is here.

Startbonus: 400 coins
Collections: 600 coins every 8 hours (7200) = 7600 coins.
The total does not include coins we can get from quests or dragon tv.
For Collecting times check this.

Dragons:
Holibreeze -E- #1205: The path costs 860 coins.
Sorcerer -VR- #316: The path costs 2825 coins + 1 key = 3285 coins.
Protector -E- #851: The path costs 3630 coins + 2 keys = 6005 coins.
Relickeeper -L- #1626: The path costs 6020 coins + 3 keys = 10830 coins.
Timelimited:
Jan 7 - 9: Holy Knight -L- #1202: The path costs 8165 coins.
Jan 8 - 9: Peacock -L- #1484: The path costs 6720 coins.

The colors on the table are the colors of the paths in the game.
Yellow fields hold Brightest Mirrors.

Thanks for marking the mirror locations.
I have all except Relickeeper. Since I have some rescued orbs of Rkeeper I'll save my coins to get an extra Holy Knight.

This is a chart based on the guide above. The sole purpose of this chart is to list the most efficient path for chests. This chart only is for event chests and does not take into account getting anything except event chests.

NOTE- This chart was approved by Bettina. If you have any questions or concerns reply to me or DM me. I would be happy to fix my guide if you believe any errors were made.