P.S. As i remember Kucoin also have the same feature that was described by lite.
you're right of course. calculating from the base currency or the other currency at the same percentage will still result in the same amount. don't know what i was thinking.
i think i got confused with trading volume and fee schedules. exchanges usually give discounts for fees according to 30-day trading volume. quoting trading volume in BTC vs in USD makes a difference because when BTC price go up, it's harder to get into the higher bracket with the same amount of trading in USD terms.