Superbuy domestic shipping

So I just ordered some stuff from Superbuy and some items had a 1Y domestic shipping price on taobao. I enter this when ordering thru Super by changing the automatic 8Y shipping fee to 1Y, and today it says that I need to pay the outstanding 7Y. Is this just how it is? Like is the domestic shipping fee stated on tao wrong?

EDIT: found out that it is because taobao had selected another area to estimate the shipping fee, not guangdong (warehouse location) which costs a bit more