We have to spit this up into two parts, so we don't have to put html tags into the translation:

<span class="quantity"><?php printf( $this->translate( 'client/html', '%1$d article', '%1$d articles', $quantity ), $quantity ); ?></span>
<span class="value"><?php printf( $this->translate( 'client/html', '%1$s%2$s' ), $this->number( $miniPriceValue ), $this->translate( 'client/hmtl/currency', $miniPriceCurrency ) ); ?></span>