To add to this
You get 72 gold and 48 Platinum each day by breeding, hatching and evolving.
And you get 3 eggs as the secind milestone in the event, in total you need to craft 12 of the 15 gems of the common dragon
To craft 12 gems in 6 days you need craft 2 platinum each day (to complete 25 for the second gem)
You will get +1000 copper and silver for harvesting from your 7 farms OR you can ask your neighbors for both Copper and silver at the start of the event
You need 80 coper and 80 silver and 4 hours to craft 2 platinum and another 2 hours to craft both gems.
You can complete (in theory) the common dragon by the day 6 and evolve it to 10 in the 7th day to get full Feathers for the monthly dragon
This event can give you two dragons ( without needed of doing the quests) and full points without breeding the common dragon.