Builder’s delight/Zero to Hero
It should be very clear which of the above is the good one. 2 books for $20 or 2 books for $3, no brainer really.
The first pack isn’t that great because you’re paying quite a bit for the runes of gold. If it were $10 for 2 book of buildings, then it would be an amazing deal. As is, I am using all my books for season bank loot so the additional runes will only be used to upgrade walls so it is completely useless.
The second pack though, is amazing. 2 book of heroes can be used for season bank or if you farm enough, just regular use. I recommend that if you have enough money for the gold pass, spend your extra money here to get the extra 2 hero levels.
Easy choice really.