Cost to keep equipment running / on


I know I could probably figure this out with a little math but wondering if anyone has already done the work.  I'm wondering how much it's costing me to leave my equipment running.  Here is the main equipment that I'm leaving on 24 hours / day.

2 SVS SB subbwoofers (not on standby, always on)
Marantz av7500 processor
Anthem PVA7 7 channel amp
2 PS Audio M700 amps

I figure the subs might be pulling alot of juice even when not in use and probably the Anthem PVA7 amp as it's class A/B I believe.

I'm in the Dallas area and I'm paying about 12.5c per kwh I believe.  

Just looking for ballpark numbers as my bill is definitely higher than I feel it should be.
dtximages
The Watt Meter Fuzztone posted above will get you exactly how much you're using with anything you plug into it. $15 and it's a great tool you can use all around your house for anything you can think  of. 
Fuzztone, thanks.  Ordered one.  Will be good to know the draw of each component.  The total running electrical cost from my gear, plus the a/c costs of cooling down the heat from from c. 25 tubes, costs me c. $100-150/ mo. In Texas.    Of course, I don’t leave the tube stuff turned on, but the dac stays on. 
Also consider funds toward wife appeasment balance after she find's out about YOUR new stuff.
All us SoCal. consumers get to look forward to a  20%-40% rate hike next year. Yippee! 

Thanks,  Southern California Edison.