public function getPerUnitAmount()
    {
        $amount = $this->getProduct()->getPrice();

        foreach ($this->getOptions() as $cartOption) {
            $amount = bcadd($amount, $cartOption->getOption()->getPrice(), 2);
        }

        foreach ($this->getExtras() as $cartExtra) {
            $amount = bcadd($amount, $cartExtra->getExtra()->getPrice(), 2);
        }

        return floatval($amount);
    }