Magento2 How to get configurable option and its price?

This code tested on Magento 2.1.4.

All you need is in getConfigurableOptions call.

67 - is a test product ID. In my installation that is a configurable product id. Change it to your product id.

Copy paste it to testfile.php and run php config.php inside magento root:

<?php
use Magento\Framework\App\Bootstrap;
require __DIR__ . '/app/bootstrap.php';
$bootstrap = Bootstrap::create(BP, $_SERVER);
$obj = $bootstrap->getObjectManager();
$state = $obj->get('Magento\Framework\App\State');
$state->setAreaCode('frontend');

$repository = $obj->create('Magento\Catalog\Model\ProductRepository');
$product = $repository->getById('67');

$data = $product->getTypeInstance()->getConfigurableOptions($product);

$options = array();

foreach($data as $attr){
  foreach($attr as $p){
    $options[$p['sku']][$p['attribute_code']] = $p['option_title'];
  }
}


foreach($options as $sku =>$d){
  $pr = $repository->get($sku);
  foreach($d as $k => $v)
    echo $k.' - '.$v.' ';
  echo ' : '.$pr->getPrice()."\n";
}

Here is the output:

Please try below code to get child product object.

 $_children = $_product->getTypeInstance()->getUsedProducts($_product);
    foreach ($_children as $child){
        $logger->info("Here are your child Product Ids ".$child->getID());
    }

Hope this will help you.