In includes/functions/functions_prices.php find at about line 300 the class "norm" and try changing it to something unique that is not already in your stylesheet
i.e.
sprice
Then add to the bottom of your stylesheet that class
.sprice {
text-size: ??em;
}
Code:
$final_display_price = '<span class="smalltext1"><s>'.TEXT_PRODUCT_MSRP.$currencies->display_price($display_msrp_price, zen_get_tax_rate($product_check->fields['products_tax_class_id'])).'</s></span><br><span class="save">'.TEXT_PRODUCT_SAVE .$currencies->display_price($save, '').' ('. number_format((($display_msrp_price - $display_normal_price) / $display_msrp_price), 2, '.', '') * 100 . '%)'.'</span><br><span class="norm">'.TEXT_PRODUCT_OUR.$show_special_price . $show_sale_price . $show_sale_discount.'</span>' ;
}else{
$final_display_price = $show_special_price . $show_sale_price . $show_sale_discount;
}
} else {
if(($display_msrp_price!='')&&($display_msrp_price!='0')){
$save=$display_msrp_price-$display_normal_price;
$final_display_price = '<span class="smalltext1"><s>'.TEXT_PRODUCT_MSRP.$currencies->display_price($display_msrp_price, zen_get_tax_rate($product_check->fields['products_tax_class_id'])).'</s></span><br><span class="save">'.TEXT_PRODUCT_SAVE .$currencies->display_price($save, '').' ('. number_format((($display_msrp_price - $display_normal_price) / $display_msrp_price), 2, '.', '') * 100 . '%)'.'</span><br><span class="norm">'.TEXT_PRODUCT_OUR.$show_normal_price . $show_special_price . $show_sale_price . $show_sale_discount.'</span>' ;
}else{