protected function _isAvailablePrice($dPrice)
    {
        $oSeries = $this->getSerie();
        $oCur = \OxidEsales\Eshop\Core\Registry::getConfig()->getActShopCurrencyObject();
        if ($oSeries->oxvoucherseries__oxminimumvalue->value && $dPrice < ($oSeries->oxvoucherseries__oxminimumvalue->value * $oCur->rate)) {
            $oEx = oxNew(\OxidEsales\Eshop\Core\Exception\VoucherException::class);
            $oEx->setMessage('ERROR_MESSAGE_VOUCHER_INCORRECTPRICE');
            $oEx->setVoucherNr($this->oxvouchers__oxvouchernr->value);
            throw $oEx;
        }

        return true;
    }