JSFiddle - React, Tailwind, and code Playground

HTML

<input id="case1" type="radio" name="cases" value="500.00" />Desktop Case ($500.00)</br>
<input id="case2" type="radio" name="cases" value="600.00" />Mini-Tower Case ($600.00)</br>
<input id="case3" type="radio" name="cases" value="700.00" />Full-Tower Case ($700.00)</br>

JavaScript

var radios = document.getElementsByName('cases');

     for (var i = 0; i < radios.length; i++) {
         radios[i].onchange = function () {
             alert(this.value);
         }
     }