After you have installed pricematch. Search catalog/product_info.php and find:-
$this_Price = $product_info['products_price'];
replace it with
if ($new_price = tep_get_products_special_price($product_info['products_id'])) {
$this_Price = $currencies->display_price($new_price, tep_get_tax_rate($product_info['products_tax_class_id']));
} else {
$this_Price = $currencies->display_price($product_info['products_price'], tep_get_tax_rate($product_info['products_tax_class_id']));
}
This has to be entered into the product_info.php file in root folder of your shop, not in the language folder so it doesn't matter what language your shop is using.
Regards
Tross