Most men have gotten in the habit of splashing on some aftershave after, well, shaving. The reason is pretty obvious: after shaving, the skin is raw and susceptible to infection; aftershave kills any bacteria on the face, keeping it clean and infection-free.
This makes sense, but the active ingredient in aftershave is alcohol. The scents and perfumes in aftershave serves no practical purpose (in fact, it could even attract bugs if you are in a climate with a lot of flies, mosquitoes, etc.)
Therefore, there is no reason to spend a lot of money on what amounts to a small bottle of smelly alcohol. Instead, you can spend a dollar or two to buy a larger bottle of rubbing alcohol which provides at least the same level of antiseptic (often more since isopropyl alcohol is available in up to 99% concentrations). In addition to getting a larger quantity of stronger alcohol, it also has the benefit that it evaporates in seconds, leaving a nice, clean, refreshing, and odorless face.
Of course some people may think that the scent is the point to aftershave and prefer to smell for hours after shaving, but rubbing alcohol is superior in several ways, so for the rest of us, it is a great alternative.