How about the Logistics costs?

How about the Logistics costs? Calculating according to the reality details:

 

For example:

 

Firstly, we calculate the volume and then compare the volume and the weight. Select the bigger one to calculate next step. If the value of the volume or weight is less than 21kg (take 16kg as an example) and the first 0.5kg is CNY 120 and additional is CNY33 for 0.5kg, then the cost equals to the CNY 120+ 15kg/0.5kg* CNY33=CNY1100.

 

If the value of the volume of weight is greater than or equal to 21kg (take 30kg as an example), then the cost equals to 30kg* the unit price.