Once you get to a high enough level, you'll be able to buy it in the market.
You have to be at level 15.
You can earn coins by collecting from the habitats, selling dragons, or by racing.
I don't know now, but my guess is when you are building your first one, you can buy more while it's building. Please reply if it actually works!
There is no dragonvale for PC
You have to earn exp by clearing things, building things, growing things, or by competing in the collesieum.
DragonVale does not have redeem codes.
DragonVale is sometimes referred to as DV.
First you have to buy the Perch of Kairos. Then, you have to collect all of the pieces you need. You can get them by sending your dragons on quests and racing in the Dragon Track. Once you get all the pieces, you'll get Kairos!
You gain exp from clearing things, completing different goals, building stuff, and by growing food for your dragons.
No you can't sell the Nursery on DragonVale.
DragonVale is a free download in the Apple App Store.
There is no such thing as a Birthstone Dragon on DragonVale