I used Power Chords in the 200-500 USD range and in the end moved to Finolex DIY
Sorry, hope this thread is not closing and I can add my 2 cents.
It depends which 200-500 USD power cords you used. As I had mentioned in a previous post, I use Chris ven Haus' VH Audio Flavor power cords in the 200-300 USD range with excellent Furutech and Oyaide connectors. They make a significant difference over the stock power cords. My wall outlets are also Furutech (30 usd per piece) and in my experience, connectors are equally or more important as cables. Agains, shielded or non-shielded etc make a difference for which equipment you use.
I don't think I will go back to either Finolex types or go forward to exotically priced and fancy cords.
I completely agree with suri's observation that you don't need anything in between the wall outlet and your equipment which will strangle the current demand. I use a single Richard Gray power conditioner (around $700) with four outlets. It is a simple device with a parallel choke. I have plugged the digital and noisy components like CDP, DVDP, processor and TV into it. It is in turn plugged into one of the several parallel wall sockets and my preamp and power amp are directly plugged into the wall sockets.
All I consider additional in future is to run a dedicated power line from may mains to the wall outlets, in line with Ben Duncan's philosophy and seconded by several others in the field.
Just my experiences, that is all.
cheers.
murali