Hi,
I saw that post you are referring to, but there is a difference in files I think, because echo JText::_('PER_UNIT'); is not there in my version of the file. Instead of that, this is what I find:
echo '</span> ';
if(isset($price->price_min_quantity) && empty($this->cart_product_price) && $this->params->get('per_unit',1)){
if($price->price_min_quantity>1){
echo '<span class="hikashop_product_price_per_unit_x">'.JText::sprintf('PER_UNIT_AT_LEAST_X_BOUGHT',$price->price_min_quantity).'</span>';
}else{
echo '<span class="hikashop_product_price_per_unit">'.JText::_('PER_UNIT').'</span>';
}
}