What's a midnight dragon worth in Adopt Me?

Excuse me, I was wondering if you could help me out with a query about Adopt Me? Specifically, I'm curious about the value of a midnight dragon in the game's virtual economy. Could you perhaps provide some insight into its worth, taking into account factors such as its rarity, demand among players, and any potential changes in value over time? I'm trying to get a better understanding of the game's marketplace and how to navigate it effectively.