JSFiddle - React, Tailwind, and code Playground

HTML

<div class="vacation" data-price='399'>
<h3>Hawaiian Vacation</h3>
<p>$399 per ticket</p>
<p>
Tickets:
<input type='number' class='quantity' value='1'/>
</p>
</div>
<p>Total Price: $<span id='Total'>399</span></p>

JavaScript

$(document).ready(function(){
$('.vacation').on('keyup click', '.quantity', function(){
  var price=+$(this).closest('.vacation').data('price');
  var quantity= +$(this).val();
  $('#Total').text(price * quantity);
});
});