Try I have a manual solution for the excl Regular Price
. You have to override the file in your theme
app\design\frontend\<VENDOR_NAME>\<THEME_NAME>\templates\product\price\final_price.phtml
and add content in to the file after the old-price
<span>
:
<span class="old-price">
<span class="price-label">excl Regular Price</span>
<span class="price-wrapper price-excluding-tax">
<span class="price">
<?php /* @escapeNotVerified */ echo $this->helper('Magento\Framework\Pricing\Helper\Data')->currency(number_format($priceModel->getAmount()->getBaseAmount(),2),true,false)?>
</span>
</span>
</span>
