Sorry for the late reply. Our Blades can last an average of 6-8 Shaves per Blade. So most likely you'll need 1 Blade per week.

Stays Super sharp through about the first four days, still useable for day 5, but you will notice the difference. I change the blade after 5 days.

Depends on often you shave. Daily shavers will go through blades faster. Whereas I shave every 2-3 days, so I go through a blade about once a month.

I have course hair and I've been on the same blade for five days still working for me

I shave seven days a week and the blade will last about three weeks.