I run a website where it is primarily free post across all items. It is a gift shop and we can post items to the gift recipient for free. But, the issue is, is that if the customer wants the item shipped to themselves. we are having to double pack the item and this increases the postage cost.
The store is Woocommerce and I am trying to find a way, that if the billing and shipping address are the same, that the customer is charged a small amount to contribute towards the postage cost. EG. postage is $3.00 if we sent to the customer but only $1.50 if we send to the recipient. I am wanting to charge the customer $1.50 if we send it to their address.
Is it possible to do this?

I have a product whose shipping price is $8 per item (1-3). I want that if anyone wants to buy more than 3, then it will charge $1 for each item. I mean if anyone wants to buy 5 items at once he will be charged ({3*8=24}+{2*1=2})=26$.

I have a product whose shipping price is $8 per item (1-3). I want that if anyone wants to buy more than 3, then it will charge $1 for each item. I mean if anyone wants to buy 5 items at once he will be charged ({38=24}+{21=2})=26$.