Seoul in spring gives you crisp nights for street food markets and clear skies to see modern landmarks like Dongdaemun Design Plaza. It is the best time to go right before the heavy summer humidity sets in, so you can walk the city comfortably.
A typical trip costs about $3,100 total. If you want to pay that off over time without interest eating into your budget, you can break it into steady monthly payments before you leave.
Remember that 18 months is a strict deadline, not free money. If you still have a balance when the 0% intro period runs out, standard interest rates apply to whatever balance remains.