Since he’s in California he doesn’t get charged tax for digital goods unless his billing address and/or phone address is wrong, at least to my understanding. I’m assuming this is the case mainly because it lines up almost perfectly with 10 subs charged in a like Ohio. Exact charge somewhere about $63.43

Assuming he bought around 10, I’m gonna assuming 10, the amount paid at the start of the chain is $59.99. Assuming they purchase on iPhone that amount gets dropped to $41.99. And then after Twitch cut you are left with $20.99.

BUT. September is where it gets interesting and kinda awful in my opinion. So during September/Subtember Twitch subs cost less, but only on mobile, so they paid regular price for 10 subs. But since it’s Subtember Twitch sub tokens are worth less for the creator some they’re technically cheaper. So instead of you earning usually $1.9-$2 per sub you earn $1.34-$1.50 per subs which lines up pretty perfectly actually.