I always buy the factory set of blades. There are many aftermarket copies, but none really meet the specifications of OEM engineering. You could pay the local shop $20-30 to sharpen them or slightly more for new Toro replacements.
Compared to other Green Lasers at this price point, this one has a lot of power. The celestial knob is of bad design because you can't stand the laser on end. Laser dot is bright. Recommend.