What about hair breakage? How often will those hairs need to be added back to the system?

Real hair breaks easily- even with your own natural living hair. Some clients purchase a system and will only need an hour of hair addition a year. Some clients are rough on their systems and will need an hour of hair addition every other month. The longer the hair is in length the more readily it will break. Learning the correct techniques and using the proper brush will reduce hair loss on your system.