Do you always keep the Amplifier powered on

Electricity in my area costs about $0.006 per kWh. For 40W it would be $0.0576 daily = $21 per year. My amplifier (total idle power = 10W) that costs me $5/year doesn't even have power switch. No power switch on my Benchmark DAC1 (also 10W) or Apple express as well. All is plugged into Furman power conditioner, including DVR set to record shows. Unplugging all three individually doesn't appeal to me. Furman has strong non-sacrificial under/overvoltage protection but I still unplug it during thunderstorms.

My bad - I was looking only at the cost of electricity.
From my electric bill:

375 KWH TOTAL@$0.0661/KWH GENERA 375 kWh X 0.06610 $24.79

but it comes to $49 with delivery charges, fees and taxes.
I made mistake, but it was a small one - 100% :)

Still, even $20 a year I can afford.

That's true it wastes electricity but so does making coffee, watching TV etc. It is for me a matter of convenience. With high power class A amp it might be a different story.

My espresso is about 1500W for 20min (minimum to warmup machine) making 0.5kWh per day (for just one coffee) while my amp and the DAC take together 20W for 24hrs = 0.48kWh. Landscape lighting takes much more, not to mention driving SUV, watching plasma TV or listening to class A amplifier. The most energy wasteful thing you can do is having a child. How many do you really need - one should be enough. :)