Questions regarding "latex hair extensions"

1. Is 210,000 won price for 16 inch latex hair extensions for whole head?

2. How long is the latex hair extensions last?

3. Should i make a reservation online even if i want to get a hair extension?

4. Will there be any extra costs more than just a hair extension price?

5. Which branch i need to visit if i want to get a hair extension service? (Hongdae, Hapjeong or Bombhead?)

Thank you,

Helen