It really helps to be a late night person when it comes to eBay. I recently got 20 blades for $35. It was a lot of money, but I feel so rich, I know I can change the blade any time and not worry about limping along with an old blade.
When I am doing a last minute auction I set the kitchen timer and then go in at the last minute, bid about 30 seconds. I have gotten some great deals on fabric that way, also.