The currency of South Korea is the Won (KRW). The country has a dense network of ATMs but many do not accept foreign cards. There are so-called Global ATMs at airports and in the most tourist areas of cities that allow for withdrawals of won. Credit cards, on the other hand, are accepted in almost all establishments. South Korea is relatively expensive compared to most Asian countries but far less than neighboring Japan.
ACCOMMODATION
You will find prices between China and Japan. Consider from €15 per person in a double room in a simple guest house in Seoul, €70 to €100 per night for a double room in an average hotel and between €200 and €500 per night in the most sophisticated hotels.
FOOD
Meals have different prices depending on the type of restaurant and area of the country. A full traditional meal in an average restaurant in Seoul can cost from €12 to €30.
INTERNET
It is one of the fastest in the world, if not the fastest, and it is available everywhere, if not free, at very affordable prices in internet cafes.