Que el peso pase de gr a kg con sus respectivos precios en woocommerce

function convert_weight_unit( $weight, $product ){
    if( $weight == 0 ) return 0;
    
    $product_id = $product->get_id();
    $base_unit = get_option( 'woocommerce_weight_unit' );

    if( $base_unit == 'gr' ){
        $multiplier = 0.001;
    } elseif( $base_unit == 'kg' ){
        $multiplier = 1;
    } elseif( $base_unit == 'lbs' ){
        $multiplier = 0.453592;
    } elseif( $base_unit == 'oz' ){
        $multiplier = 0.0283495;
    } else {
        return $weight;
    }

    $new_unit_weight = $weight * $multiplier;

    update_post_meta( $product_id, '_weight', $new_unit_weight );

    return $new_unit_weight;
}

add_filter( 'woocommerce_product_get