Nervous about the budget for treatment in Korea... how do I plan it?

Hi friends, I'm Yanti from Jakarta. I'm seriously considering going to Korea for aesthetic treatments, but honestly, I'm a bit overwhelmed with budget planning. This is my first time leaving the country for a treatment like this, so I'm really unsure how to calculate all the expenses.

What I'm confused about is how long I should stay for treatment and recovery? Should I take a week or two off? Flights, accommodation, meals... all of that adds up to a lot, multiplied by the treatment cost itself. Can anyone share their experience on how to plan? I'm worried about running out of budget and feeling stressed instead of better.

Can anyone also give me some insight on the best time to go? Is it more worthwhile to go during the off-season? And is it better to go alone or with a friend so we can split the costs? Sorry for the many questions, I'm just trying to be realistic with my budget and don't want to regret my decision later.