Safety Blades Vs. Razor Blades

I’ve always wondered if I really do save myself money by using safety razor blades instead of the more modern Schick or Gillette razors. So I created a TCO calculation (note: .ods open document format spreadsheet, you may need to do a “save link as”) to understand which is cheaper.

An assumption: I ignored the cost of the actual razor, since both are approximately the same cost.

In the end, my conclusions are:
1. The TCO is highly sensitive to the value you assign to your free time.
2. The TCO hinges on the amount of time you spend shaving with a safety blade vs. a normal razor. Most people shave a little faster with the razor cartridges.
3. The TCO is also affected by the number of uses you get out of the safety razor versus the modern razor blade.