Hello,
the whole purchase, i.e first product $4 the remaining 4 $2 each.
If I correctly understood what your wanted to do, if you want the total shipping price to be $12 (4 +

:
- if you only set a price per product of $2 your total will be $10
- if you set a shipping price of 4$ and a price per product the total will be $14
- so in your case a solution can just be to set a shipping price of $2 and a price per product of $2 so that the total can be 12$ and the first product will be charged $2 (shipping price) + $2 (price per product)