How to change Paypal's shipping cost method to base cost + per item cost

Not sure what your workflow is but its more controllable if you pass your own shopping cart information to the paypal gateway.

Normally you would set a range of shipping costs for the items - 1 item - £6.00, 2-5 items - £8.00, 6-10 items - £12.00. A more realistic approach as you would expect shipping costs to reach a ceiling at some point.

<?php

/ add up quantity total in cart - form field

$quantity_in_cart = 6;

// add up items in cart

$items_in_cart = 2;

// 1 item in cart - shipping £6.00

if($quantity_in_cart === 1) {

$shipping = 6.00;

$shipping = number_format((float)$shipping, 2, '.', '');

}

// Between 2 - 5 items in cart - shipping £8.00

if($quantity_in_cart > 1 && $quantity_in_cart <=5) {

$shipping = 8.00 / $items_in_cart;

$shipping = number_format((float)$shipping, 2, '.', '');

}

// Between 6 - 10 items in cart - shipping £12.00

if($quantity_in_cart > 5 && $quantity_in_cart <=10) {

$shipping = 12.00 / $items_in_cart;

$shipping = number_format((float)$shipping, 2, '.', '');

}

?>

// Below would be the result output via a loop from a php cart session or you could use a javascript array

// item 1 - these are paypal hidden field names

<input type="hidden" name="item_name_1" value="Item 1">

<input type="hidden" name="amount_1" value="15.00">

<input type="hidden" name="quantity_1" value="4">

<input type="hidden" name="shipping_1" value="<?php echo $shipping; ?>">

// item 2 -these are paypal hidden field names

<input type="hidden" name="item_name_2" value="Item 2">

<input type="hidden" name="amount_2" value="20.00">

<input type="hidden" name="quantity_2" value="2">

<input type="hidden" name="shipping_2" value="<?php echo $shipping; ?>">