A Kaspa transaction is charged the largest of its three mass measures. Not the total. Storage mass, compute mass, and transient mass are each computed separately, and the fee follows whichever is biggest. Adding them together overstates what a transaction costs, sometimes by a lot, and that mistake shows up in explainers often enough to be worth naming. If a fee estimate looks high, check whether whoever built it summed three numbers that were never meant to be summed. $KAS