From past experience, I know that it's most of the time cheaper to buy the packs from HE rather than from the game. As you say, with the difference it price, you will probably easily be able to buy the corresponding promo cards. Nice move to rebalance your deck for the future modern changes!
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Yes my friend I think the price difference is too high right now. For example if I buy 30 packs from Hive engine I will save almost 21$ and most likely I will be able to buy 1 BCX of legendary promo. If I buy 30 packs from presale I will have 3 guaranteed rare promos but only 30% of finding 1 legendary promo.
thanks for your comment and considerations and also thanks for picking my post
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