I agree $60 is expensive but $20-30 is a fair price. The screen protector requires a more complex installation than others to ensure good clarity, good fit and to retain touch sensitivity. It comes with custom LOCA glue (see Xfactor for similar glue), a UV lamp, and a specialized installation tray to make it easier.

You could purchase these items separately DIY as others have done but there are downsides to it too. It has the potential to be cheaper, but you'll spend more researching the right glue and screen protectors to buy. The installation won't be as easy due to the lack of a installation tray. Finally the final result won't be as good, but it'll be close. It's hard to find TGP without dot matrix and good oleophobic coating for the S8.

I used this also for the extra screen protection with a glass screen protector on top

10ml LOCA UV GLUE - Xfactor PREMIUM GRADE LOCA (Liquid Optical Clear Adhesive) - LOW Viscosity !! https://www.amazon.com/dp/B00IOPYLJE/ref=cm_sw_r_cp_apa_dJsmBb9R18FFM