The helmet was found on the positions of the machine-gunners near Kharkov, this is in the Ukraine. On the nineteenth minute of the video, it shows how this helmet was found.
— 10 USD by Russian Post
— 25-40 USD by courier service EMS
— 30-40 USD by Russian Post
— 40-60 USD (depends on customer's country) by courier service EMS
What is the difference between Russian Post and EMS courier service? Read here - link