When I had to shave I look for discounts on the disposable ones.I got a few true razor blades that uses the blade you see in movies for dividing up lines of coke. Those I am saving to pass on to my kids one day. I also have a beard trimmer with an adjustable guard.
I typically use the trimmer to shave my head once a year,then let it grow back. I use it for other body hair to keep that in check. Nothing like wearing a short sleeve shirt in the summer and have hair sticking out the sleeve.
I also use the beard trimmer without the guard for the face to knock the hair down, then the disposable razor to get down to the skin. I toss the razor after using it.
Although Im somewhat of a germ freak I knew many guys when I worked at the bank who took a bag into the bathroom and pretended they were at home. They brushed their teeth, shaved and did like a lite sponge bath. I remember one guy telling me how he plans his poops at work to save toilet paper. I guess that makes your living cheaper, but you are still using someone else water, energy, toilet paper, etc.