Helmet and buckle were found in a deep hole, near the German cemetery in the Gorodishche district of Stalingrad (now Volgograd) in 2018. Since both items belonged to the same soldier, they are sold together
— 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