Shopping Cart total qty and fee

[SusanW]

Dear All,

 

In the Shopping Cart of store, I need a fee line show up based on total order qty.

The formula is

total order qty * $5/1000

With a minimum charge of $15 if total order qty is less than 3000.

 

For example, if customer order

 

500 product A

3500 product B

1000 product C

= 5000 qty

 

$5/1000 * 5000 = $25

 

If they ordered only 500 product A and 1000 product C, total order qty is 1500 which less than 3000, the fee would be $15 (the minimum).

 

Customer will pay be credit card by the correct fee.

 

Please tell me how to do that.

 

Thank you very much!

 

Susan