Using USPS single rate box for various quantities.

[TimFromPhoenix]

My customer is using USPS flat rate boxes to ship out their product. They can get approximately 12 items in each box. Each box costs about six dollars to send. I am trying to figure out a way to charge the customers for shipping based on those facts.
If they ship from 1 to 12 items they get charged six dollars. If they ship from 13 to 24 items they get charged $12, etc.
This is only one type of product they have. Other products are shipped using regular UPS by weight.

I am up for any creative ideas you might have.

Thanks ahead of time.

[Ajeh]

You can customize the UPS shipping module to count how many of the 1 Product is in the cart and build a calculation on the every charge add $6.00 to the UPS shipping ...

Set this Products weight to 0 so that it does not get charged by UPS and then add the calculated cost based on how many are in the cart of this 1 Product to the $cost in the UPS shipping module ...

[TimFromPhoenix]

My client is using USPS and not UPS. I looked in the USPS module but didn't really see any kind of options at all for customization.

[Ajeh]

You technically are not then getting a Real Time quote from USPS but rather saying on the screen:
USPS shipping $XX.XX

This can be done with the Item Rate item shipping module but you need to customize it to take the item quantity and divide it by 12 and round up on the result and multiply by 6.00 to get the shipping cost ...

This can be best done by setting the Item Rate to 6.00 and then customizing the code to change the count of how many are in the cart to be divided by 12 and multiplied by this rate ...

You need to customize this section of the code in the Item Rate item shipping module:

      // adjusted count for free shipping
      $item_total_count = $total_count - $_SESSION['cart']->free_shipping_items();
      $this->quotes = array('id' => $this->code,
                            'module' => MODULE_SHIPPING_ITEM_TEXT_TITLE,
                            'methods' => array(array('id' => $this->code,
                                                     'title' => MODULE_SHIPPING_ITEM_TEXT_WAY,
                                                     'cost' => (MODULE_SHIPPING_ITEM_COST * $item_total_count) + MODULE_SHIPPING_ITEM_HANDLING)));