All aluminum oxide belts on the market are basically the same in quality. The ones I am using from G.L. Pierce ($1.50 each - get the ones with the thick backing)are just as good or better than the Klingspor($3.00 + each)I purchased from a well known knife supplier before. They both wear out and become slick at the same rate. I am sick of the way that well known knife suppliers are gouging prices on most everthing they sell. I think they are trying to make a killing out of the surge in part-time makers who have other incomes and make knives mostly as a hobbie. Don't fall for it. If you are going to spend considerable funds on knifemaking supplies, shop around for the best prices on everything. Other wise you will be ripped off by the major, well advertised suppliers. All of this being said, I do believe it is worth the money to purchase good quality ceramic belts (3m or Norton). They do 30 to 40 times the work of aluminum oxide belts (on steel, don't use them on handle material), at only 2 to 3 times the cost. I think G.L. Pierce has these also. Nuff said.
