JSFiddle - React, Tailwind, and code Playground

HTML

<div class="shop">
    <div><input class="cost" type="text" /></div>
    <div class='shop_items'><table>
    <label class="selected">1</label>
    <label class="selected">1</label>
    <label class="selected">1</label>
    <label class="selected">1</label>
    </div>
</div>
<div class="shop">
    <div><input class="cost" type="text" /></div>
    <label class="selected">1</label>
    <label class="selected">1</label>
    <label class="selected">1</label>
    <label class="selected">1</label>
    <label class="selected">1</label>
    <label class="selected">1</label>
    <label class="selected">1</label>
    <label class="selected">1</label>
    
</div>

JavaScript

$(".shop").each(function () {

    var sum = 0;

    $(".selected", this).each(function () {

        var item = $(this).text();
        sum += parseFloat(item);

    });

    $(".cost", this).val(sum);

});