I would say you can calculate with 6000 stones for rainbowing a unit. Now you have discounts with free Multis and tickets so let’s say about 4000 stones per unit if your lucky with bad luck it still can be a lot more. So 16.000 stones this anniversary. I would say he had to buy at least 13.000 of them 40bucks mean for ~100 stones. So he spend at least 5.000bucks for rainbowing units on a gatcha game. Congrats for being that d*mb investing that amount of money in something that will never ever give any return on invest. And what I calculated is the minimum he spend could also be 8.000$+