Real quick on this one and good idea by the way. 5 mos ago I made some calls about that and spoke to bic. After becoming friends with the guy he said " we are not in the razor business, we are in the razor blade business. "
They don't want them to last longer.
At $18.00 for 8 blades and their cost at $0.09 each. They are making a killing.
U can't believe they have us paying what we do. And who needs 4 blades! Just stroke twice on a double and drop the price. But their marketing did their job