This Ballistic glass screen protector from "Tech Armor" on amazon is really cheap ($16) for galaxy S5 and it's one of the best glass protectors technologies. I bought it for my gf last week.
Tech Armor Samsung Galaxy S5 Premium Ballistic Glass Screen Protector - Protect Your Screen from Scratches and Drops - Maximize Your Resale Value - 99.99% Clarity and Touchscreen Accuracy
-Mina
Tech Armor Samsung Galaxy S5 Premium Ballistic Glass Screen Protector - Protect Your Screen from Scratches and Drops - Maximize Your Resale Value - 99.99% Clarity and Touchscreen Accuracy
-Mina