Power Consumption analyzer

I know this has been talked about in here before, but i can not find the thread. So i looked for them an again and this is what i found.

I wanted Something that will tell me how much electricity/$ My machine is burning, say on a one time use/ dayly / monthly basis.

I have found the <A HREF="http://" target="_new">Watts Up?</A> which seemed to be excatly what i was looking for. But its was pricy.
Then i found the <A HREF="http://www.safehomeproducts.com/SHP/SM/Electricity_Monitor.asp" target="_new">Kill a Watt</A> and and the Watts Up? here. the Kill a Watt is in the right price range!

Before i buy one i thought i might ask any of you what you thought of these pruducts...

Does anyone have one?
Why is the Kill a Watt so much less?



<b><A HREF="http://www.digitalgunfire.com" target="_new">DigitalGunfire-Industrial EBM</A></b>
ASUS P4S8X-P4 2.4B - 2x512M DDR333 - ATI 9500Pro - WD80G HD(8M) - SAMSUNG SV0844D 8G HD - LG 16X DVD - Yamaha F1 CDRW

nope. when you overclock, you cease caring.

<b>My Computer is so powerful Sauron Desires
it and mortal men covet it, My Precioussssssss!

Regards,
Mr no integrity coward.</b>

roflmao--good one, bro

found it over in the..you guessed it power supply section..not the exact same thread I saw it in to start with but the same link I believe....
<A HREF="http://www.jscustompcs.com/power_supply/" target="_new">http://www.jscustompcs.com/power_supply/</A>

what are some recommended power sources that are not to pricey. I saw one thread (may have been the one where I first saw that link) that recommended one that was about $30. Was it enermax?