How much power would this use (idle)

Roughly how much would all of this use? (idle)

  • Motherboard: Asus A88XM-Plus (mATX)
  • Processor: AMD Athlon 760k (@4.3 GHz, stock cooling)
  • Memory: Crucial Ballistix Sport 8GB (2x4GB, 1600 MHz, CL 9)
  • Graphics Card: Sapphire 7850 (1 GB)
  • OS Drive: Kingston V300 SSD (128 GB) 
  • Operating System: Windows 7 Home Premium (x64)
  • Storage Drive: None
  • Power Supply: XFX Core Edition 80+ Bronze (450W)
  • Case: Aerocool DS Cube mATX (Red)
  • Monitor: Samsung S22C300HS 21.5" (LED, 1080p, 5 ms) 
  • Mouse: Sharkoon Fireglider Laser Mouse (@800 dpi) 

Also, does anyone else leave their computer on overnight? I do because I like the ambient sound it makes and I have a digital clock screensaver (black background light green text, which is very convenient for me to glance at and check the time as it is near perfectly in my line of vision)  
 
I just don't want my parents to pay a lot of money for this? Is it equivalent to a light bulb or two? If so, then that's fine. We leave are told to few lights in the house on anyway (intentionally) lol 

In all honesty probably under 250W. You can leave it on overnight. It won't even be noticable power bill. If you have electric heat turn your thermostat down two degrees and you'd save more power than your PC uses. So it really is fine. 

So it won't really have an impact on the power bill? I mean if it's like £20 ($30) per year, that's not much of a difference.