When I bought my Martelli cutter I was told the blade would last one year and the same for the replacement blades.
I'm still on my original blade 4 years later but don't use it all the time as I am a 'switch hitter' and bought the left handed version of Martelli because that is my dominate hand.
Now that I have the rotating rotary mat I will probably use the Martelli more often.
Peggy
Freezing in Florida
but NO SNOW!