I also have wondered about the blade sharpeners. If you have a JoAnns that you shop at, I have a couple near me, take advantage of the coupons that are in the sales flier or mailer to buy the more expensive items. I have bought many rulers, templates and other items at 40% and 50% off that way. They also have ALL thread 1/2 price at times, that is when I purchase all of my multicolored/specialty threads. Haven't used them all yet, but have them when I need them.
JoAnns will also honor a coupon from Michaels, but not for fabric.