Some advice for the new mini-expansion bundle

After looking around forums and youtube videos I see that many of the players plan to buy the expansion directly with the 2000 gold. I was initially against it because I think none of the legendaries will see consistent enough play, but I believe you will get more dust overall by buying it instead of just buying 20 packs of darkmoon faire.

However there is something very important I think players should do, and that is opening all those packs you saved first. If the game works as it should, the no duplicate rule will not happen if you already have the cards, so you'll probably end up getting around *4 of all the commons and some extra rares. This is pretty important because I believe some of those common and rare cards are potential cards to be hit by nerfs.

Arbor Up , [Hearthstone Card (Libram of Judgement) Not Found], Hysteria(it creates a 7-turn kill combo in wild, a nerf like this has happened before), ALL of the rogue cards are pretty powerful, and Backfire are some of the most dangerous cards of the expansion. You can even add some others to the list even though I would disagree with it.

So TLDR: Open packs from DMF first before buying the mini-expansion, it will probably give you some extra dust.

EDIT: Just now I saw some comments in another thread about how you could risk getting a duplicate legendary by following this method, and I agree to an extent, I think your decision should depend on what legendaries you want from this set. If you still have a legendary from the basic Darkmoon Faire collection you want then maybe you don't want to open packs first. You can consider it if you got a legendary recently too, as the chances are lower.