public function setPrice($amount)
    {
        $tax    = $this->getTaxRate()  / 100;
        $taxAmount = $amount * $tax;

        $this->prices = [
            'pretax' => round($amount, 2),
            'tax'    => round($taxAmount, 2),
            'net'    => round($amount + $taxAmount, 2),
        ];

        return $this;
    }