Hi, some food for thought.
What about a dragon swap / trading style space where players could either straight swap their unused dragons for other dragons in that tier or sell them, for some kind of bankable currency / credit. The currency could be saved and used for dragons that are being offloaded /sold by other players.
There could be some level capping etc so a new player couldn’t get hold of an emerald mythic, for example, but they could most definitely save for a dragon just above their current level.
Recycling is a big topic these days, let’s not just stop at plastics and metals!