As said of female characters in cards of this type (due to the Japanese culture itself), its value is considered high, but "relatively" more accessible compared to other cards that it has in the current Metagame, where we have Marnie as one of the most expensive
For one, unlike certain other pack-based online competitive games, spending money doesn't really gain you any meaningful advantage: there's no online transfer market, for instance, where you can hawk your wares for in-game megabucks to then buy an otherwise unobtainable good squad
Hedron Crab is certainly the more flexible of the two because you can use it to enable your own graveyard, but both of these cards are fantastic mill engines for 60-card formats
Four mana is a lot for either a CounterspellCounterspell or a BoomerangBoomerang, much less a slightly better version of both, and Doc AurlockDoc Aurlock isn't even providing a discount on that half of the card