There ARE nice $4 receptacles ...
I have used and like Pass & Seymour heavy duty receptacles.
They grip well, and maintain that grip for many years. In fact some are still in my system.
On the audiophile level ($40) are (I own 2) Acme silver plated. And those cryoed Hubble
sold on Audiogon.
I would just say if you do not own aftermarket powercords.. It is hard to think of aftermarket Duplex AC as mattering.
And then the real test is: If you can't hear it, Does it matter to you???
And then the famous: "if you can't hear NO ONE ELSE CAN EITHER" fallacy.
And I have to say it took me many years and a LOT more money invested in my stereo before I could hear a lot of this stuff. When I jumped from $1K or $2K a pop to $5K a pop for components. yeah it became a lot easier to hear trivial stuff like IC and powercords.. (though I confess I have not really bothered to check if I CAN actually hear differences in outlets. IC yeah. powercords yeah.. So I am old and lazy. Too lazy to test myself with outlets.
Though I can say Leviton outlets are worthless crap.