"I could buy a manga and get change with the same money to buy that frappe"

i think every thing in japan costs less but thats because everyone is paid way less than places like america

higher demand = lower cost for a wider market

otaku culture is still fairly niche outside of japan, even more so when you consider how many people prefer streamable anime over physical copies of manga, so there's a bit of a luxury cost to having the hobby imported (or translated and printed locally)