Hi
My english is very bad but try this
put this code in your product.tpl
<span id="our_price_display" class="price" itemprop="price" content="{$productPrice}">{convertPrice price=$productPrice|floatval}</span>
the result is :
<span id="our_price_display" class="price" itemprop="price" content="20.00">20,00 €</span>
regards