[Ryland]

220 volt electric water heater timers cost about $30 last I checked, I got mine used from my parents who installed it in the early '90's before they got a forced vent gas water heater and put the vent fan on a timer, doing that to their LP water heater cut their LP gas use in half.
I had a hard time getting a solid pre-timer electrical use on my house but it would appear as if my timer cut the electrical use of the water heater by 1/3 to 1/2, or about $10 to $15 per month in a house with three adults.
How mine is set, it comes on before our first water use of the day, so at 5:30am it comes on, 7am it turns off, 7:30am my alarm goes off and I get up, at that point any any cold water entering the tank stays cold until about 3pm when the timer comes on again, turning off at 4:30pm
The reason that the timer comes on for 1.5 hours at a time is that my timer has large tabs with little thumb screws on them and that is as close together as I can get them, with this set up we have never been left with cold water, my co-home-owner said that she would pay for half of any improvements like this as long as it didn't impede on comfort, so no cold showers! on guest we had took a shower at 4 am, before the timer clicked on and she said it was still warm enough to shower, not steaming hot but nothing to complain about, so why worry about turning it off at all? because the greater the heat difference the greater the heat loss from the tank, a 125F tank of water is going to cool faster then a 80F or 90F degree tank of water in a 60F degree room and so an untimed water heater will reheat that tank of water a few times per day, middle of the day, middle of the night and will have cooled off enough that it will reheat again most likely right about the time you wake up and take a shower, so let it sit cool/cold all day and all night then heat it up right before you want it.
On demand water heaters tend to have a 20-25 year payback, putting a timer on your tank has a 2-4 month pay back, even a $100 timer is going to be a year and that is a good investment!
You can also get solid state relays for $20-$60 that are heavy enough to handle an electric hot water heater, this would open up your options for adding manual remote controls or automated controls, something I'm trying to work on.