woocommerce add to cart & adjust price

gistfile1.php

<?php

// add product to cart with additional data
$woocommerce->cart->add_to_cart($post->ID, $quantity = 1, $variation_id = '', $variation = $entry[1], $cart_item_data = array(
  'hire_price'=>123,
)); 



// make sure additional data sticks in the session
add_action('woocommerce_get_cart_item_from_session', function($cart_item, $values) {
    if (isset($values['hire_price'])) {
        $cart_item['hire_price'] = $values['hire_price'];
    }   
    return $cart_item;
}, 10, 2); 

// dynamically set the price in the cart
add_action('woocommerce_before_calculate_totals', function($cart_object) {
    foreach ( $cart_object->cart_contents as $key => $value ) { 
        if(isset($value['hire_price']) && $value['hire_price']) {
            $value['data']->price = $value['hire_price'];
        }   
    }   
});

// display the data in the cart item
add_filter('woocommerce_get_item_data', function($other_data, $cart_item) {
    if(isset($cart_item['hire_price']) && $cart_item['hire_price']) {
        $other_data[] = array('name' => 'Hire Price', 'value' => woocommerce_price($cart_item['hire_price']));
    }   
    return $other_data;
}, 10, 2); 

// save the extra data to the order
add_action('woocommerce_order_item_meta', function($item_meta, $cart_item) {
    if(isset($cart_item['hire_price']) && $cart_item['hire_price']) {
        $item_meta->add('Hire Price', $cart_item['hire_price']);
    }   
}, 10, 2);