Crates

I currently have 30 Halloween crates on the ready.
I wish to obtain, at the bare minimum:
1 Field shovel Halloween
However, what I am aiming for is:
1 Gatling Gun Halloween
2 Field shovel Halloween
I have almost enough ZP to buy 30 more Halloween crates.
However, I also want to try and get other ZP crate items, and perhaps upcoming limited edition crates.
Should I buy an extra 30 Halloween crates, or hope for the best with my current 30 crates?

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