I've found that slashing bread dough will dull a blade about as fast as raw chicken (that is, pretty fast.) While working as a pro baker I made my own lames by taking a double edged razor blade and threading a wooden coffee stirrer through the middle. It also gave the blade just the right bit of curve to slash the dough perfectly. I went through 3-4 blades a week, slashing several hundred loaves.
You make out cheaper than buying the fancy lames.
You make out cheaper than buying the fancy lames.