node.js steam priceHistory

Question

I've found a similiar question and an answer, but still failed.

Question; How to retrieve steam market price history?

I've tried setting the Cookie key to my steamLogin session id but failed, what I currently have;

var request = require('request');
request({
    url: "http://steamcommunity.com/market/pricehistory/?currency=1&appid=730&market_hash_name=AK-47 | Case Hardened (Minimal Wear)",
    method: "GET",
    header: {
        'Cookie': 'steamLogin=76561198120000019%7C%7CD85DD7A94E93BBE4F8B511F4982D077FA25B585A'
    }
}, function(error, response, body) {
    if(error) {
        console.log(error);
    }
    console.log(body);
});

The array is just empty or it just spews out random strings. To access the pricehistory, you have to be logged into steam, hence why I'm trying to set the steamLogin cookie key. I just don't understand why it isn't working for me.

Thanks in advance, Ouli.