This ebay seller was posted by a board member:
http://www.ebay.com/itm/100-45MM-ROT...#ht_801wt_1161
They also have smaller packs of the generic blades at a bit more $$ per blade. I ordered 10 and have used them and given them to some quilting friends. They have worked well for me. My friends and I are going to order 100 next time & split the order.
If you are considering this, I would order a small number and see how you like them before ordering large number.