Power Cord: Need to choose from these, please help

Friends,
I am on a quest to buy a nice power cord for my source.
To start with I do not believe in Shielding theories as I have heard quite a few unshielded power cords being more silent and clean than shielded ones. Moreover I have also found a lot of shielded power cords sucking the life out of music making it slow and boring.
So, I have a budget of around $500, give or take 20%. I am equally at ease buying used and new cords. I am not looking for a power cord to equalize sound, so it has to be neutral and true. After some research, the power cords I have shortlisted are:

1. Cardas Golden Reference
2. ESP Essence Reference (used)
3. Omega Mikro Planar Active (used)
4. Purist Audio Dominus (used, this can still overshoot my budget)
5. Telwire (used)

I have heard none of them :(
But I have only heard the ESP cord among these and liked them quite a lot. But they are rare in the used market. Cardas is the most commonly available cord among these and I am surprised to see them getting sold within couple of days of getting listed, are they that special ?
Omega Mikro looks like another brand which is highly spoken about in circles and the used market price does fall in my budget well.
Purist is in this list simply because it has got such rave comments in this forum that I really could not stop considering them and I am waiting for what you guy have to say about Dominus in the company of other good cables (some of them over achievers).

Kindly suggest and if possible give me a comparative signature sound of these so that I know what to expect from each. I understand that at the end system synergy is the key but I feel my system is fairly neutral and a brief idea of the sonic signature of these cables can help me decide one among them a lot more easily. Also do feel free to add your recommendations to this list.