Maze explanation is here.

Startbonus: 400 coins
Collections: 600 coins every 8 hours (19800) = 20200 coins.
The total does not include coins we can get from quests or dragon tv.
For Collecting times check this.

Dragons:
White Princess -L- #1441: The path costs 28900 coins.
Dejavu -R- #454: The path costs 750 coins.
Princess -VR- #307: The path costs 2585 coins + 1 key = 2965 coins.
Old General -VR- #475: The path costs 2605 coins + 2 keys= 4955 coins.
Icewind -E- #611: The path costs 3800 coins + 3 keys = 7750 coins.
Arid -E- #931: The path costs 4035 coins + 4 keys = 8565 coins.
Protector -E- #851: The path costs 6525 coins + 5 keys = 13645 coins.
Aquaking -E- #732: The path costs 6700 + 6 keys = 15705 coins.
Kingpin -L- #1191: The path costs 10440 coins + 7 keys = 24970 coins.

Timelimited:
July23-25: Brave Sword -E- #326: The path costs 2590 coins. Here we get puzzle moves.
July26-28: Thief -R- #202: The path costs 7850. We can get food here.
July28-30: Mystic Blizzard -E- #344: The path costs 5300 coins. Here are flightstamps.
July31-Aug2: Patriot General -L- #614: The path costs 9500 coins.
Aug1-2: Deputy -L- #1556: The path costs 9895 coins.

11 day event and only 1 new dragon? That's strange.

The only dragons I don't have the new one & Kingpin. Kingpin requires too many coins so I won't get that. Will get Deputy & walk Brave Sword & Mystic Blizzard paths just for the puzzle moves & flight stamps. What I do with the rest of my coins depends on how many I get from the puzzle & where I can get the best goodies.

Tables are up.