$400. You consider the smaller merp packages to have an intrinsic penalty, to punish the player for not being a whale. And yet that $400 will only give you a

$400. You consider the smaller merp packages to have an intrinsic penalty, to punish the player for not being a whale. And yet that $400 will only give you a 63.4% chance of getting a rare item. An 80% chance will cost you $640, a 90% chance costs $920, and a 99% chance a whopping $1800. On average, you'll spend $400 per rare item. But can you imagine all your whale players spending $1800 each, and that 1% of them might not even have a rare after all that? Can you imagine being that whale that spends $1800 and gets nothing? If I were developing that game, I would certainly add an "odds pressure" escape valve to the randomness, so that both your overall win-loss record and your recent win-loss record influence your odds of winning on the next play. But as long as we're doing that, we might as well also set up an intermittent reinforcement schedule that essentially guarantees one win in the first five boxes you open, one in the next five, the next ten, the next fifteen, etc.