Algol Plus Ltd

add_filter( "wpo_prepare_item", function ( $item, $product ) {
  $item['item_cost'] = $product->get_price();

  return $item;
}, 10, 2 );

add_filter( "wpo_update_cart_loaded_product", function ( $loaded_product, $item ) {
  $loaded_product['item_cost'] = $item['data']->get_price();
    $loaded_product['readonly_price'] = $item['data']->get_price();

  return $loaded_product;
}, 10, 2 );

add_filter( 'wpo_cart_item_is_price_readonly', "__return_true", 10, 0 );