Handling Fee Plugin

Here’s the code. I just want the input field to store data on both sides of the decimal point, and then pass it to the corresponding field in the Checkout.

Thanks!

add_action( 'add_meta_boxes', 'wdh_add_handling_metaboxes' );
function wdh_add_handling_metaboxes()
        {
			add_meta_box('wdh_handling_meta_side', 'Handling', 'wdh_handling_fee', 'product', 'side', 'default');
		}

function wdh_handling_fee()
        {
			global $post, $woocommerce ;
			echo '<table class="form-table">';
			// Noncename needed to verify where the data originated
			echo '<input type="hidden" name="wdc_handling_fee_noncename" id="wdc_handling_fee_noncename" value="' .
			wp_create_nonce( plugin_basename(__FILE__) ) . '" />';
			echo '<tr>';
			echo '<th style="width:40%"><label for="lead_name"><strong>Handling fee:</strong></label></th>';
			// Get the location data if its already been entered
			$wdc_handling_fee = get_post_meta($post->ID, 'wdc_handling_fee', true);
			// Echo out the field
			echo '<td><input type="text" name="wdc_handling_fee" value="' . $wdc_handling_fee  . '"  size="30" style="width:60%" /></td>';
			echo '</tr>';

			echo "</table>";	

		}

// Save the Metabox Data
function wdh_save_handling_meta($post_id, $post)
        {

			// verify this came from the our screen and with proper authorization,
			// because save_post can be triggered at other times
			if ( !wp_verify_nonce( $_POST['wdc_handling_fee_noncename'], plugin_basename(__FILE__) )) {
			return $post->ID;
			}

			// Is the user allowed to edit the post or page?
			if ( !current_user_can( 'edit_post', $post->ID ))
				return $post->ID;

			// OK, we're authenticated: we need to find and save the data
			// We'll put it into an array to make it easier to loop though.

			$lead_meta['wdc_handling_fee'] = $_POST['wdc_handling_fee'];

				// Add values of $lead_meta as custom fields

				foreach ($lead_meta as $key => $value) { // Cycle through the $lead_meta array!
					if( $post->post_type == 'revision' ) return; // Don't store custom data twice
					$value = implode(',', (array)$value);
					if(get_post_meta($post->ID, $key, FALSE)) { // If the custom field already has a value
						update_post_meta($post->ID, $key, $value);
					} else { // If the custom field doesn't have a value
						add_post_meta($post->ID, $key, $value);
					}
					if(!$value) delete_post_meta($post->ID, $key); // Delete if blank
				}

		}

add_action('save_post', 'wdh_save_handling_meta', 1, 2); // save the custom fields

class WC_Settings_Tab_Handling
     {

    	 public static function init() {
        add_filter( 'woocommerce_settings_tabs_array', __CLASS__ . '::add_settings_tab', 50 );
    	}

		public static function add_settings_tab( $settings_tabs ) {
			$settings_tabs['handling'] = __( 'Handling', 'woocommerce-handling' );
			return $settings_tabs;
		}
	}

	WC_Settings_Tab_Handling::init();

add_action( 'woocommerce_settings_tabs_handling', 'wdh_settings_tab_handling' );

function wdh_settings_tab_handling() {
    woocommerce_admin_fields( wdh_get_settings_handling() );
}

function wdh_get_settings_handling() {
    $settings = array(
        'section_title' => array(
            'name'     => __( 'Handling Settings', 'woocommerce-settings-tab-handling' ),
            'type'     => 'title',
            'desc'     => '',
            'id'       => 'wc_settings_tab_handling_section_title'
        ),
        'title' => array(
            'name' => __( 'Costs Added...', 'woocommerce-handling' ),
            'type' => 'select',
            'desc' => __( '', 'woocommerce-handling' ),
            'id'   => 'wc_settings_tab_handling_type',
			'options'  => array(
								'per_item' => __('Per Item - charge handling fee for each item individually', 'woocommerce' ),
								'per_order' => __('Per Order - charge handling fee for the entire order as whole', 'woocommerce' ),
								'per_max_item' => __('Per Max Item - Charge handling fee for the entire order as whole(ony max handling will charge)', 'woocommerce' ),
								)
        ),

        'section_end' => array(
             'type' => 'sectionend',
             'id' => 'wc_settings_tab__handling_section_end'
        )
    );
    return apply_filters( 'wc_handling_settings', $settings );
}

add_action( 'woocommerce_update_options_handling', 'wdh_update_settings_handling' );

function wdh_update_settings_handling() {
    woocommerce_update_options( wdh_get_settings_handling() );
}

/*
** Add handling fee to cart
*/

add_action( 'woocommerce_cart_calculate_fees','wdh_charge_handling_fee' );
function wdh_charge_handling_fee() {
     global $woocommerce;

     $handling_type = get_option('wc_settings_tab_handling_type');
	 foreach($woocommerce->cart->get_cart() as $cart_item_key => $values ) {
		$_product = $values['data'];
		$handling[$_product->id] = intval(get_post_meta($_product->id, 'wdc_handling_fee', true));

	 }

	 if($handling_type == 'per_max_item')
	    {
		  $fee = max($handling);
		  if ( is_admin() && ! defined( 'DOING_AJAX' ) )
          return;

     	  $woocommerce->cart->add_fee( 'Handling', $fee, true, 'standard' );
		}
	 elseif($handling_type == 'per_order')
	    {
		  $fee = array_sum($handling);
		  if ( is_admin() && ! defined( 'DOING_AJAX' ) )
          return;

     	  $woocommerce->cart->add_fee( 'Handling', $fee, true, 'standard' );
		}
	elseif($handling_type == 'per_item')
	    {
			foreach($handling as $key => $item)
			        {
						$p_name = get_the_title( $key );
						$h_title = 'Handling for '.$p_name;
						$woocommerce->cart->add_fee( $h_title, $item, true, 'standard' );

					}
		}else{
			$fee = array_sum($handling);
		  	if ( is_admin() && ! defined( 'DOING_AJAX' ) )
         	return;

     	  	$woocommerce->cart->add_fee( 'Handling', $fee, true, 'standard' );
		}

}

I believe the problem is this line:
$handling[$_product->id] = intval(get_post_meta($_product->id, 'wdc_handling_fee', true));

This is using intval() to make an integer from the value stored. Storing real numbers can be problematic when currency is involved. You might consider storing the fee as 1/100 units instead of ones units (cents instead of dollars if US currency), so store 550 instead of 5.50. On output then the intval() is fine, but then value is divided by 100 and output using print_f() to avoid weird fractional values like 5.49999999984

Thanks. I actually reached out to the developer about modifying the code, but they want $150 to get off the proverbial couch.