I buy blades in large quantities super cheap on ebay. They do not last as long as the 'big name' ones but they still are so much cheaper that it is a good deal. They only time I buy at a store is with a 60% coupon and that is for the odd size or specialty blades. I am curious as to why your blades aren't 'lasting too long'. You should be getting a reasonable use time out of blades.