JSFiddle - React, Tailwind, and code Playground

HTML

<table width="50%" border="0">
  <tr>
    <td width="20%"><div align="center">item</div></td>
    <td width="20%"><div align="center">New Activation</div></td>
    <td width="20%"><div align="center">Commission</div></td>
    <td width="20%"><div align="center">Price</div></td>
    <td width="20%"><div align="center">MEID</div></td>
    <td width="20%"><div align="center">Number</div></td>
  </tr>
  
   
   
              <td><div class="styled" align="center">
                <select name="item" id="item">
                <option value="">Phones/Devices</option>
                    <option value="">-----APPLE-----</option>
                  <option value="200.00" value2="20.00" value3="iPhone4">iPhone 4 8GB</option>
                  <option value="225.00" value2="20.00" value3="iPhone416">iPhone 4 16GB</option>
                  <option value="250.00" value2="20.00" value3="iPhone432">iPhone 4 32GB</option>
                  <option value="275.00" value2="20.00" value3="iPhone464">iPhone 4 64GB</option>
                  <option value="300.00" value2="20.00">iPhone 4S 8GB</option>
                  <option value="325.00" value2="20.00">iPhone 4S 16GB</option>
                  <option value="350.00" value2="20.00">iPhone 4S 32GB</option>
                  <option value="375.00" value2="20.00">iPhone 4S 64GB</option>
                  <option value="400.00" value2="20.00">iPhone 5</option>
                    <option value="500.00" value2="30.00">iPhone 5C</option>
                    <option value="625.00" value2="30.00">iPhone 5S</option>
                    <option value="">-----BlackBerry-----</option>
                    <option value="75.00" value2="5.00">Curve</option>
                    <option value="100.00" value2="5.00">Bold</option>
                    <option value="225.00" value2="10.00">Q10</option>
                    <option value="250.00" value2="10.00">Z10</option>
                  <option value="">-----HTC-----</option>
                   ...

JavaScript

var phoneEl = document.getElementById('item');
var activationEl = document.getElementById('item1');

function updatePrice() {
    var phonePrice = +phoneEl.value;
    
    price.innerHTML = "$"+phonePrice;
}

function updateCommission() {
    var commission = +phoneEl.options[phoneEl.selectedIndex].getAttribute("value2"),
        activationPrice = +activationEl.value,
        totalCommission = commission + activationPrice;
    
    cost.innerHTML = "$" + totalCommission;
}

phoneEl.onchange = function() {
    updatePrice();
    updateCommission();
};

activationEl.onchange = function() {
    updatePrice();
    updateCommission();
};