How buy anniversary collection event with 72 euro 

I bought anniversary collection event for 72 euro and I get heirloom shards.
This is the cheapest way to get heirloom shards.
I bought 2 bundle with 12 item for 7500 apex coin.
I bought 4 epic item with crafting material for 1600 crafting material.
I get 2 free pack from anniversary challenge.
And I bought 6 pack from shop for 4200 apex coin.
12+4+2+6=24 item=heirloom shards