I have bought these blades locally. I am very excited to share the fact that this couple just recently began listing them. I have used 1 blade instead of 5 of the most famous brands. I highly recommend looking at these. Especially since I see they have a guarantee and free shipping. These cryogenic blades are incredible and well worth every penny.
http://www.ebay.com/itm/10-Cryogenically-Hardened-at-320-degrees-45mm-Rotary-Cutter-Blades-/130794381627?pt=LH DefaultDomain 0&hash=item1e73f3e13b
You can most likely find it under 10 Cryogenically hardened 45mm rotary cutter blades.