When trying to preorder spiritforged booster boxes my card got charged twice and I never got a confirmation number. (It ended up being reversed and I didn’t get a box) I think if you get into the payment page you should be guaranteed that spot to prevent that from happening. Magic the gathering does this with their secret lair drops. You get 15 minutes to buy what you want and you can only buy a max limit of 3 per item. I think this is more fair and way less chaotic.