Maze explanation is here.
Startbonus: 400 coins
Collections: 600 coins every 8 hours (5400) = 5800 coins.
The total does not include coins we can get from quests or dragon tv.
For Collecting times check this.
Dragons:
Celtic -R- #374: the path costs 860 coins.
Key for Night Forest on step 9 (460 coins).
Night Forest -E- #770: the path costs 2825 coins + key = 3285 coins.
Key for Longhorn on step 16 (1915 coins).
Longhorn -E- #331: the path costs 3630 coins + 2 keys= 6005 coins.
Key for Autumn Spirit on step 19 (2435 coins).
Autumn Spirit -L- #1396: The path costs 6020 coins + 3 keys = 10830 coins.
Sep 29 - Oct 1: Harvest -L- #1299: the path costs 8165 coins.
Sep 30 - Oct : Heaven -L- #852: the path costs 6720 coins.