So, yesterday I saw a Fluffpaxa egg end up being sold on auction for something like 200 PC, now I saw one for 24 currently.

Could just be someone starting the auction incredibly low, but does it have rare color groups or something? It doesn't seem to evolve.

It's an auction, so prices tend to fluctuate. We've had some start pets go for 100+ or 200+ sometimes. It just all depends on who's bidding and what money they're willing to spend.

Fluffpaxa is considered a rare pet. I really like it's design and find them incredibly cute and full of personality. Their color group also includes rose, which is a big reason I want one personally. They have no known evolution. There's a whole guide in Game Guides that gets into the particular details of the pets, if you're ever curious!