If anyone still has access to DragonStory:NewDawn here's a great glitch...log into New Dawn to feed your dragons and ALL are cost pattern "A"!!!!
I discovered this a long time ago, but won't share it on Team Lava's forums because I'm sure it will be fixed. Any dragon can be Level 10 for 9,615 food!
Just be sure to go back to the current Dragon Story version before breeding/hatching because you cannot breed/hatch any *new* dragons from the New Dawn version, you'll repeatedly get "common" dragons.
**New Dawn is no longer available to download, so if you don't have it you will have to do some sincere searching to find a download link.**