하루에 얼마에요?  How much per night?

You usually do not book a jjimjilbang, you pay, enter, when you leave, you can't enter again without paying. So when you wanna stay the next day again, you just pay again. In a jjimjilbang you usually do not have rooms, though there are some where you can have a room. When you do not have a room, you have no privacy and you can't leave for food. There are only some jjimjilbang which offer food. Staying there could be stressful for several days. Staying in a cheap motel would be better and more convenient. I really like jjimjilbang, but I never stayed for several days.