Crates have 5 slots, 2 for Consumables, 1 for a blue or better item, 1 that can be anything, and a 5th bonus slot that is purple or better.
Crates have 5 slots, 2 for Consumables, 1 for a blue or better item, 1 that can be anything, and a 5th bonus slot that is purple or better.
More precisely crates have a chance at a 5th slot. If you get a 5th card it will be purple or better, but the majority of crates will only give you 4 cards.
It's worth factoring in the 5th slot, especially if you're looking at opening a large number of crates like the OP is, but you'd need to know the probability of getting a 5th slot, as well as what can drop from it.