In this section output by tpl_product_info_display.php
HTML Code:
<!--bof Product Price block -->
<h2 id="productPrices" class="productGeneral">
<span class="map_pricing">$398 for SALE price, add to cart</span></h2>
the entire span is one block so the price cannot be styled separately. The PHP code will have the price output followed by (probably) a constant which holds the text " for SALE price, add to cart". You may be able to find the define for that constant and add new <span> tags around that part like this
PHP Code:
define('MAP_TEXT_WHATEVER_NAME', '<span class="noMap"> for SALE price, add to cart</span>');
In your stylesheet
Code:
.map_pricing {text-decoration: strikethrough;}
.map_pricing .noMap {text-decoration: none;}