Add line item showing total cost
I created a line item using hook_uc_line_item() then added the line item in the hook_uc_order().

Final products looks something like:

/*
 * Implement hook_uc_line_item()
 */
function my_module_uc_line_item() {

  $items[] = array(
    'id' =&gt; 'handling_fee',
    'title' =&gt; t('Handling Fee'),
    'weight' =&gt; 5,
    'stored' =&gt; TRUE,
    'calculated' =&gt; TRUE,
    'display_only' =&gt; FALSE,
  );
  return $items;
}

/**
 * Implement hook_uc_order()
 */
function my_module_uc_order($op, $order, $arg2) {

  // This is the handling fee. Add only if the user is a professional and there
  // are shippable products in the cart.
  if  ($op == 'save') {
    global $user;

    if (in_array('professional', array_values($user-&gt;roles))) {


      // Determine if the fee is needed. If their are shippable items in the cart.
      $needs_fee = FALSE;
      foreach ($order-&gt;products as $pid =&gt; $product) {
        if ($product-&gt;shippable) {
          $needs_fee = TRUE;
        }
      }

      $line_items = uc_order_load_line_items($order);

      // Determine if the fee has already been applied.
      $has_fee = FALSE;
      foreach ($line_items as $key =&gt; $line_item) {
        if ($line_item['type'] == 'handling_fee') {
          $has_fee = $line_item['line_item_id'];
        }
      }

      // If the cart does not already have the fee and their are shippable items
      // add them.
      if ($has_fee === FALSE &amp;&amp; $needs_fee) {
        uc_order_line_item_add($order-&gt;order_id, 'handling_fee', "Handling Fee", 9.95 , 5, null);
      }
      // If it has a fee and does not need one delete the fee line item.
      elseif ($has_fee !== FALSE &amp;&amp; !$needs_fee) {
        uc_order_delete_line_item($has_fee);
      }
    }
  }
}