I don’t have an electric razor, but I’d like to know what you do when the blades go dull. Do they sell replacement blades, or do you simply toss a $60 item and buy a new one? At that rate, I’d be buying a new one everyday. OK, I live in a cave, and I have yet to forgive GEICO… 
- Jinx
There are several systems of electrically powered shaving implements, so I don’t know what exactly do you mean by electric razor, but most of them indeed have easily replaceable blades. On the other hand their construction usually makes them to stay sharp for very long - at least months and often even years.
I think electric razor technology has moved on, but I remember my dad’s razor used “foils” rather than blades, which he replaced every so often. They were like thin metal sheets with holes in, which would move over one another rapidly. The hair would stick through the holes and get scissored off, I guess.
While I generally hate electric razors because they cannot do as good as a job as a nice sharp sextuple-bladed Mach XXIV razor, I do use them on occaison.
One of the things I’ve found is that they last longer and stay sharper longer if you clean the heads/blades fairly frequently.
And yeah, you can get replacement blades for much cheaper than the price of another new electric razor.
Many electric razors have foils and cutters (the cutter block operates under the foil). When I use an electric razor I tend to replace the foils every six months or so (they break eventually, which can lead to some face-cutting fun). The cutter blocks don’t need replacing so often - maybe every 12-18 months in my experience, and many manufacturers now provide a small container of oil to apply to them occasionally as well. As an example, a combined foil and cutter pack for most Braun razors comes in at around £15 ($30).
Which gets into an interesting question about whether it’s worth replacing the cutter and foil on an inexpensive razor.
OTOH the last time I looked at blades for my Mach 3, they were running about $2 per cartridge. Replace them once every 10 days or so and the annual cost can be a wash.
Ten days? Mine sometimes make do for a month, but then (a) I’m too lazy to shave every day and (b) I am then amazed at how good a new blade feels. 
I am actually quite tempted to get an electric razor, for those mornings when I really don’t have time to wet-shave but would like to arrive at the office looking slightly less like a scarecrow.
I find a wet shave better when I haven’t shaved in a while or when I have time to spare. Otherwise, a dry shave works for me (and I’ve found the shave to be no worse quality, unless you’re using a really cheap and nasty razor). While there is a small outlay every 6 or so months, it means I’m not buying new blades or foam.
I’ve always used Philishave types with 2 or 3 rotating cutters. The cutters have lasted for years, I’ve have never replaced them. They appear to be self sharpening.
I think I’m on razor #4 after 20+ years of shaving daily. I must admit that the cost of replacement cutters vs a new razor prompted my last purchase. I’d already put new batteries in twice, and knowing my luck, after putting in new cutters, something fatal would of broke soon after.