What do you think of this power cord?

The power you have going from your panel to your plug is just as important. If you haven’t run dedicated lines to your outlet, upgrading your power cords would be a waste of money IMHO

You didn't mention whether or not you have a power conditioner. I had a very slight hum/buzz with the volume turned up and nothing playing until I got a power conditioner and the noise vanished. It also provides protection form spikes, like lightning hits.

I'd recommend one, and as far as a power cord goes, I think $100-150 is right. According to the cable company, the longer the power cord, the better (opposite of interconnects and speaker cables), but don't make loops out of excess cord as that creates a magnetic field. Try to keep cables from touching each other, especially if running parallel. I have entry level signal,  gutwire and wire world, and they're fine. Just make sure it is flexible. My signal one is thick and hard to maneuver.

"....According to the cable company, the longer the power cord, the better...."

Do you really believe that?

Maze Audio REF4 is a very good power cord in terms of materials, design and build quality, making it a very good value. It is comparable to cords costing four times as much. The reason? Buying directly from the manufacturer. And it will get you at least 2/3 of the way toward the sound quality of the “insanely expensive” cables such Shunyata. I use both in my system. 
I also like the Signal Cables Silver Reference ($250 with upgraded Furutech connectors.) That one replaced the PS Audio AC-12 power cord that costs $1,000.