Hi,
Well, you can cross the retail price with simple CSS code.
For example:
.hikashop_product_msrp_price .hikashop_product_price{ decoration: line-through; }
You can also use translation overrides to change the text before the prices. And you can use some more CSS to put both prices on the same line.
If you want to go further, then you would have to edit the file "listing_price" of the view "product" and change that block of code which handles the display of the retail price:
<span class="hikashop_product_msrp_price hikashop_product_price_full">
<span class="hikashop_product_msrp_price_title"><?php
echo JText::_('PRODUCT_MSRP_BEFORE');
?></span>
<span class="hikashop_product_price"><?php
$mainCurr = $this->currencyHelper->mainCurrency();
$app = JFactory::getApplication();
$currCurrency = $app->getUserState( HIKASHOP_COMPONENT.'.currency_id', $mainCurr );
$msrpCurrencied = $this->currencyHelper->convertUniquePrice($this->row->product_msrp,$mainCurr,$currCurrency);
if($msrpCurrencied == $this->row->product_msrp)
echo $this->currencyHelper->format($this->row->product_msrp,$mainCurr);
else
echo $this->currencyHelper->format($msrpCurrencied,$currCurrency).' ('.$this->currencyHelper->format($this->row->product_msrp,$mainCurr).')';
?></span>
</span>
Having discounts on variants is something we want in the future.