Stripe Checkout - Charge Amount

Question

I'm following the basic example from https://stripe.com/docs/checkout/guides/php and having problems seeing how the amount can be determine and use in the creation of the charge.

I would have thought/hoped that using the token I created I would be able to retrieve the amount associated with it and pass this amount into \Stripe\Charge::create()?

For example I have some PHP/template code that generates a form for a range of products

# index.php
<?php require_once('./config.php'); ?>

<form action="charge.php" method="post">
  <script src="https://checkout.stripe.com/checkout.js" class="stripe-button"
          data-key="<?php echo $stripe['publishable_key']; ?>"
          data-amount="{$MY_AMOUNT}" data-description="One year's subscription"></script>
</form>

$MY_AMOUNT will change according to the product that is being displayed

Now charge.php receives the post and creates a charge but what is the correct way to specify the value (currently 5000) of the 'amount' index of the array?

<?php
  require_once('./config.php');

  $token  = $_POST['stripeToken'];

  $customer = \Stripe\Customer::create(array(
      'email' => 'customer@example.com',
      'card'  => $token
  ));

  $charge = \Stripe\Charge::create(array(
      'customer' => $customer->id,
      'amount'   => 5000,
      'currency' => 'usd'
  ));

  echo '<h1>Successfully charged $50.00!</h1>';
?>

So, there are 2 approaches I can think of here

1. A PHP page per product with hardcoded amounts - No thanks

2. Passing the key and amount as hidden variables, these doesn't seem "right" as it can easily be changed, e.g. below

   <form action="charge.php" method="POST">
       <script
           src="https://checkout.stripe.com/checkout.js" class="stripe-button"
           data-key="{$key}"
           data-amount="{$amount}"
           data-currency="GBP"
           data-address="true"
           data-name="{$name}"
           data-description="{$description}"
           data-image="logo.png">
       </script>
       <input name="myHiddenKey" type="hidden" value="{$amount}" />
       <input name="myHiddenName" type="hidden" value="{$name}" />
   </form>
   

Answer 1

No the token is just a precheck to allow you to make a charge, the amount being passed through to Stripe in the Javascript is only used by Stripe for display purposes. Stripe_Charge::create is where you actually pass through the amount.