So I bought the mystery box 1 spin for 20 gold and got to try my luck on a mystery box spin. I thought, oh it's a gamble, but I can probably figure out the loose timing to get a weapon.....Next I buy 10 spins for 180 gold, figuring I'll save 20 gold....pressed my 1st spin, received a prize, but then all I could do is press "claim" and the game automatically assigned me another prize and took another spin.
In short, I got to use timing my spin to get the prize I wanted ONCE out of 10 spins I purchased.
So my advise to mystery box players; buy 1 spin at a time. At least you'll have the chance to use your timing skills; otherwise you're just playing a slot machine without a handle/button.
iPhone 4, usually.