If it's a holiday, you can go to Cheongna International City Station by train and go to the Araseo Sea Lock Gate Certification Center. The fare is 90,000 won for 2 people. The truck costs 70,000 won and you must make a reservation in advance. After arriving in Busan, you can return it at a Busan hotel or at the Nakdong River Estuary Good Bank Certification Center. 3 units are 120,000 won, 4 units are about 130,000 won.
Prices may change depending on circumstances.