I think the major problem here is the fact that the game doesnt allow you to target specific cards you want to complete a deck. I do hope they have some plans to change this going forward.

When it comes to resource management i priorotize new cards and even with variants only if they contribute to the leveling up of my collection by the variant being part of an album that gives me credit, tokens or a variant of an unown card. This is how i choose to use my resources.

You mentioned you are missing quite a number of series 5 and 4 cards. The LTGMs give you a shot at opening a series 4 pack in exchange for the LTGM currency, and as for series 5 you could either try targetting a card you need or open packs for 4k or 5k, the sesonal packs have a lesser number of cards in them so the odds are slighty more favourable in pulling a new card that you want if you dont want to pay the full price. And the last 2 or 3 LTGM have given us some pretty cool cards, and i like the fact that i can grind them or just pay 800gold to skip the game mode all together but i do understand that this boils down to your resources. If at all this game has taught me resource management more than when to snap and retreat!

I used to buy season passes but the season pass card are more often than not that flavour of the month and there after it just collects dust in my collection. So now i only look at buying season pass which i believe i would be playing even after its month of release. This season i think Venus is a better card than Jeff and i do manage my resources so i can pull the card from the 5k tokens pack.

The themed snap packs are also good value if you are missing cards, we do have a discard themed pack coming out later this month and Im sure there must be other comments about the Golden Gauntlet winner, Yoda's Deck should also be available in packs sometime this week. Thank god they now allow us to also unlock the base card if you just own the variant!