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:
Quartz -R- #257: The path costs 860 coins.
key for Water Storm on step 9 (460 coins),
Frozen Ruby chest on step 7 (255 coins), Frozen Handle chest on step 10 (580 coins).
Water Storm -VR- #483: The path costs 2825 coins + 1 key = 3285 coins.
key for Zodiac Aquarius on step 16 (1915 coins).
Frozen Ruby chest on step 13 (1335 coins).
Zodiac Aquarius -E- #296: The path costs 3630 coins + 2 keys = 6005 coins.
key for White Princess on step 19 (2435 coins).
Frozen Handle chest on step 11 (1055 coins) and step 22 (3085 coins).
White Princess -L- #1441: The path costs 6020 + 3 keys = 10830 coins.
Frozen Ruby chest on step 16 (3185 coins) and 19 (4485 coins), Frozen Handle chest on step 20 (4970 coins).
Timelimited:
18.-20.: Boreas -L- #1004: The path costs 8165 coins.
Frozen Handle chest on step 21 (6350 coins), Frozen Ruby chest on step 23 (7535 coins).
19.-20.: Absolute Zero -L- #1374: The path costs 6720 coins.
Frozen Handle chest on step 20 (5605 coins), Frozen Ruby chest on step 21 (6150 coins).
Explanation for the table:
orange = chest for ruby
blue = chest for handle
black = for keys
purple = timed path