I've had that in mind all along. It may seem silly, but I have always blown on razors to remove excess water, and stored them in a dry place (not in the shower or by the sink). And now I store the razor in olive oil after blowing it off. I have always used one blade (Mach 3) 3 weeks at the very least and up to two months.
I'd also like to see evidence that shows a Fusion blade can last 3 months.