blah.php

<?php
	error_reporting(E_ALL);
	ini_set('display_errors', 1);

	$response = [
		'success' => false,
		'lowest_price' => null,
		'volume' => null,
		'median_price' => null
	];

	if(isset($_GET['item']))
	{	
		try
		{
			$q = new PDO('mysql:host=localhost;db=mydb');
			$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

			$q = $db->prepare('SELECT * FROM items WHERE name = :name');
			$q->execute([
				'name' => $_GET['item']
			]);

			if($q->rowCount())
			{
				$url = 'https://steamcommunity.com/market/priceoverviewy_/';
				$params = [
					'currency' => '1',
					'appid' => '730',
					'market_hash_name' => $_GET['item']
				];
				$headers = [
					'User-Agent' => 'LBGT IceWwasel/1.0'
				];

				$req = new HTTP\Client\Request('GET', $url, $headers);
				$req->addQuery($params);

				$cli = new HTTP\Client;
				$cli->setOptions(['redirect' => true]);
				$cli->enqueue($req)->send();
					
				$res = $cli->getResponse();
				if($res->getResponseCode() == 200)
				{
					$result = $res->getBody()->toString();
					$result = (array) json_decode($result);
					$response = array_merge($response, $result);
				}
			}
		}
		catch(PDOException $e)
		{
			//deal with db errors
			var_dump($e);
		}
		catch(Exception $e)
		{
			//deal with any errors
			var_dump($e);
		}
	}

	header('Content-Type: text/json');
	echo json_encode($response);