how about just manually in the template?
e.g. templates/flexible_darkmart/html/com_virtuemart/productdetails/default.php after line 493
echo preg_replace('/style="display : block;"/',' ',$this->currency->createPriceDiv('salesPrice', '', $this->product->prices));
echo ' incl. TVA';
echo $this->currency->createPriceDiv('discountAmount', 'COM_VIRTUEMART_PRODUCT_DISCOUNT_AMOUNT', $this->product->prices);
gives like in the screenshot..
Cheers