I would say, look to grab the rares or commons that are useful - start with that then go in if your determined... So, crystal seer from chaotic compliance. Crystal seer is both good for farming (also gift of the martyr...) and gameplay. If you're not looking for fun decks i.e. non meta.... (harpies fck grounds will get what's coming to them...) then I suggest straight up - land of the Titans.
The staples he's on about are: order to charge, sphere kuribo, lady bug of doom and sonic bird... Very difficult to get any of those, staples tho... Valerie's rage for staples, ultimate rising is for wallets... I'll drive into each pack - what cards to get....
(save money guide) So from Neo impact. If you can x2-3 magical merchant. That is all... (learn how to use the graveyard) Next Valerie's rage - gem gem gem, love this pack... Skull lair, chaos zone, awesome ultra rares and SR. Chaotic compliance, crystal seer and gift of martyr. (Prometheus deserves a mention) Flame of the tyrant, Sargent electro... Venus... That's it...
To put it very simply: Land of Titans for the security orb and fun deck - it will get you to silver rank... Valkerie's rage for staples, ultimate rising for secret pass of treasures - good luck! (I'm hungover)
Ugh. This takes forever, but here are a few of the faster options.
-Dawn of Destiny: Phoenix decks are weakening, but you can build a powerful deck after buying 240 packs at most. That is, 3x the whole box. You'll want to emphasize:
---Heavy Knight of the Flame
---Super Rush Headlong
Everything else should come along with it as it's either rare or normal.
-Galactic Origin: You can build a Gladiator Beast deck pretty quickly and easily from even one complete set of Galactic Origin. However, you'll be missing A LOT of removal power. You'll need:
-A copy of the UR Heraklinos
-3 copies of Laqueri
-3 copies of Andal
Cyber Angel is... somewhat doable without buying tons of packs. In general you would need:
-Crimson Kingdom: one set of the box should let you build a Paladin farming deck mostly...
-Ultimate Rising: Sonic Bird and fodder for a Yugi farming deck
-Neo Impact: Senju
-Galactic Origin: You might want to buy three full sets of this for Saffira...
Basically, building a meta deck takes a lot of time and a lot of gems to buy ONLY the packs you need for the deck you want. The question of which box to buy isn't a simple 1:1 answer. You really want UR cards from all over the map. I do apologize if this is an info overload, but there's no easy answer. Hope you find a path that works for you and what you want out of the game!