In short, the SF decks are worth the cost. 250 SC for 60 much more essential cards, where previously we had to buy Elemental packs for gold since the CotC+DP decks contained cards that were seldom used in deck building. Even if we have collected most of the cards already, the Vess and Raikka decks are the best way of converting SC into gold (for buying cards from the next set )

250 SC is the equivalent of 2 and a half pack value of an Elemental deck, which is around 6,000 G. (2400 x 2.5)

So for new players, I'll revise the guide soon taking into account that most of the merchant purchases aren't needed anymore, hence saving a lot more of the $19.99 you all started out with.