Jquery: Сумма 2 функций/блоков

    <?php
    $_GOODS= array("goods"=>array(1=>"Гучи", 2=>"Суприм")); //Товары
    $_GOODS_PRICES = array("goods_prices"=>array(1=>"10000 грн.", 2=>"5000 грн.")); //Цены
    $_COLOR = array("goods"=>array(1=>"Красный", 2=>"Белый")); //Товары
    $_COLOR_PRICES = array("goods_prices"=>array(1=>"2000 грн.", 2=>"3000 грн.")); //Цены
    ?>
        <form action="#" method="post" name="order">
        <section>
        Товары:
        <select onchange="getVal(this);" >
            <option disabled selected>Выберите товар</option>
            <?php foreach($_GOODS['goods'] as $key => $value):?>
            <option data-price="<?= $_GOODS_PRICES['goods_prices'][$key] ?>" value="<?= $value; ?>"><?= $value; ?></option>
            <?php endforeach;?>
        </select>
        Цена:
        <span id="price">Не выбрано</span> <!--Цена 1-->
        <script>
        function getVal(sel) {
            document.getElementById("price").innerHTML = sel.options[sel.selectedIndex].dataset.price
        }
        </script>
        </section>
        <section>
        Цвет:
        <select onchange="getVal_2(this);" >
            <option disabled selected>Цвет</option>
            <?php foreach($_COLOR['color'] as $key => $value):?>
            <option data-price="<?= $_COLOR_PRICES['color_prices'][$key] ?>" value="<?= $value; ?>"><?= $value; ?></option>
            <?php endforeach;?>
        </select>
        Цена:
        <span id="price_2">Не выбрано</span> <!--Цена 2-->
        <script>
        function getVal_2(sel) {
            document.getElementById("price_2").innerHTML = sel.options[sel.selectedIndex].dataset.price
        }
        </script>
        </section>
        <section>
        Общая сумма:
    <span id="price_sum"></span> <!--1+2 цена-->
    <script>
    var p1 = document.getElementById("price").innerHTML;
    var p2 = document.getElementById("price_2").innerHTML;
    var sum = document.getElementById("price_sum");
    sum.innerHTML = Number(p1) + Number(p2) + " грн.";
    </script>
        </section>
        <input type="submit" name="submit" value="Отправить" />
        </form>