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
You can name Elspeth Conquers Death (you know, the best) and Elspeth Conquers Death will itself pay you back
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
Set us as preferred Pikachu
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
You might only have three or four lands total but feel that tempo is more important and therefore cycle your land on turn one to increase your odds of getting a two drop