Originally Posted by
RTWSTARALLIANCE
Bus 6030 at arrival level gate 6B or 13A. Depending on the number of people trying to buy tickets inside go outside near the gate and there are additional ticket booths with one or two windows open. Remember to have cash unless you have a Korean transportation card.
The ticket booths at ICN also take credit cards. But the vendors right at the bus stop and the driver on the way back is cash only.