Thanks for your kind reply.
But In my opinion, I’m wondering why do unit price for Without Clicking – (#7 & #8) 380 pairs/carton and clicked insoles are the same price at USD 1.40/pair.
Without clicking must be a lower price because you can save costs for hiring labour.
If so, it means STS have to bear the higher costs of goods by implication, which in fact we do not need to pay.