You cant kick Skydiver for 0, which is an important drawback from making it too powerful, but its still strong nonetheless
For that reason, I think its particularly worth it for Rakdos Goblin decks, which can easily run the above combo, while still being able to effectively use First Day of Class when its used in a more straightforward manner
You can use it on the post-combat main phase and only have used up three net mana for the Dragon that turn
As the crown jewel of the Eeveelution trio and the flagship card of the entire Jungle set, Flareon consistently tops price lists and shows no signs of slowing down
Klauth may be expensive for its stats, but this Gruul Dragon will provide some serious ROI before long if it has a decent board state backing it up
They are rarity, condition, and popularity among collectors.