What is the fastest way of traveling to Busan from Seoul?
KTX is the quickest way to reach Busan or Pusan from Seoul. It takes a little over three hours, which is pretty fast. A one-way ticket will cost around 40,000 to 50,000 won ($40~$50 USD).
Go to the Korail website (click here), click the Inquiry button, select a train, and put down your information. (If you are an American, choose 'America.') You can make the payment with a credit card.