This is a dark horse of the Theros Beyond Death set. You can't really open Ironscale Hydra in a normal booster pack, but one can find it only in Theme Boosters and Collector Boosters.
This means that the price has been formed mainly due to the rarity of the card rather than the actual power, although some players predict it to do really well in certain Standard decks.
Usually, these kinds of scenarios generally develop in a similar fashion. As soon as the card gets circulated a bit, the price drops heavily. You should expect the same outcome for Ironscale Hydra.