JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-3.1.0.min.js"></script>
<label>
  <input type="radio" name="delivery" id="target" speed="fast">
  <span class="label label-success">Fast Delivery</span></label>
<div id="output">10</div>
<div id="original" value="10" style="visibility:hidden"></div>



<label>
  <input type="radio" name="delivery" id="target2" speed="normal">
  <span class="label label-success">Regular Delivery</span></label>

JavaScript

$('input:radio[name="delivery"]').change(function() {
  alert($('#original').attr('value'));
  $('#output').html($('#original_cost').attr('value'));
  if($(this).attr('speed') == 'fast'){
  	var extra_shipping_fee = 40;
  	var current_price = parseInt($('#original').attr('value'));
		var new_price = current_price + extra_shipping_fee;
    $('#output').html(new_price);
  }else{
  	$('#output').html($('#original').attr('value'));
  }
  
})