Smart Water Heater

This mission for knowledge came after a buddy suggested I get a timer for my water heater, and said I couldn't get one for under a hundred bucks.

My goal is to come up with the most inexpensive device, that will activate the water heater on a schedule, and record it's power consumption.

Arduino Board - Not sure which one to get. Cheapest one that'll do the job for now. I read I could program a chip using an arduino board, and use that for an even cheaper version.
220Vac - 12VDC 1A transformer = $3.40
220VAC 40A DPDT Relay = $6.80
ACS712 Module Current Sensor 220Vac 30A = $6.99
LCD Display with keypad = $3.48

$20.67 without the board, just on a quick part/price search.

Am I on the right track as far as the parts I'd need?

Any guidance would be greatly appreciated.

"ACS712 Module Current Sensor 220Vac 30A"

Where does it say "220Vac".

Leo..

Low power consumption, low price: these guys are hard to beat when it comes to switching. Power consumption not included yet, though.

Dremmer:
Am I on the right track as far as the parts I'd need?

Hard to say.
I take it you're on 220V AC, single phase? That would make it a boiler type, rather than an instant on type. What's the rated power of your heater? What kind of on/off schedule do you need?

and said I couldn't get one for under a hundred bucks.

Heavy duty and reliable 10 kW water heater timer for $40

Dremmer:
$20.67 without the board, just on a quick part/price search.

Am I on the right track as far as the parts I'd need?

http://www.ebay.com.au/itm/DIN-Rail-Digital-LCD-Power-Programmable-Timer-Time-Switch-Relay-AC-220-240V-FA1-/112415481460?epid=902971182&hash=item1a2c7c1e74:g:yw8AAOSw42dZIqbG
$AU 15.88, and battery backup included at no extra charge.