[shan]

you could add this

{if $product[product].list_price gt 0}
{math equation="100-(price/lprice)*100" price=$product[product].price lprice=$product[product].list_price format="%d" assign=discount}
<font class=MarketPrice>{$lng.lbl_market_price}: <s>
{include file="currency.tpl" value=$product[product].list_price}
</s></font>

{/if}