Its about surprise power-level jumps and mismatched expectations
The financial value of these drops was never really in doubt
For example, if you discard a card to cast Tormenting Voice, then copy it with Reverberate, you do not need to discard and additional card for the copy, since you're not casting it
If youre looking to build a storm deck, keep in mind that free and cheap spells are key
In fantasy, its important to establish the stakes, what will be lost if the grand adventure fails
But the power level upgrade from Quicksilver Amulet or Elvish Piper to Timmy, Power Gamer is barely noticeable and easily disrupted as a 1/1 4-mana dork