WooCommerce Extra Fee

I have found this snippet of code which works perfectly, but its adding a 0.5% fee per product added to the basket in the category of 19, instead of having is as a percentage, I need a round figure.

function df_add_ticket_surcharge( $cart_object ) {

    global $woocommerce;
    $specialfeecat = 19; // category id for the special fee
    $spfee = 00.00; // initialize special fee
    $spfeeperprod = 0.05; //special fee per product

    foreach ( $cart_object->cart_contents as $key => $value ) {

        $proid = $value['product_id']; //get the product id from cart
        $quantiy = $value['quantity']; //get quantity from cart
        $itmprice = $value['data']->price; //get product price

        $terms = get_the_terms( $proid, 'product_cat' ); //get taxonamy of the prducts
        if ( $terms && ! is_wp_error( $terms ) ) :
            foreach ( $terms as $term ) {
                $catid = $term->term_id;
                if($specialfeecat == $catid ) {
                    $spfee = $spfee + $itmprice * $quantiy * $spfeeperprod;
                }
            }
        endif;  
    }

    if($spfee > 0 ) {

        $woocommerce->cart->add_fee( 'Ticket Concierge Charge', $spfee, true, 'standard' );
    }

}

add_action( 'woocommerce_cart_calculate_fees', 'df_add_ticket_surcharge' );

Weather there is 10 or 1000 products of a certain category in the basket, the fee just needs to be a total sum of £10.