power cord affects on video?

MY early adapter $4000 (on sale) 42" Sony Plasma picture improved with a $50 Pangea AC14SE back when I first put an aftermarket cord on it. The color got brighter, the grain decreased.                
Currently I have a Pangea AC14SE mk2 signature (2m $80) on the plasma from my Furman REF 20i power conditioner.                       
Worthwhile improvement.                
I would say for a TV the law of 'diminishing returns' hit pretty fast. I would never spend more than $100 for a TV powercord.               
(and one reason I stick with Pangea.. audio like video, diminishing returns. How far into the fractal zoom you think is worthwhile?? For me it stopped at $450 a pop. Most around the $100/$150 mark.

How do you know it’s the law of diminishing returns? Hint: You don’t. In audio the only constraints are the ones in your head. I suspect yours is a case of penny wise, pound foolish. No offense.

Goeff is 100% correct on penny wise pound foolish. I scrimp on many things, Just so I can then burn money like a fool on others. I rent cheap, eat cheap, dress cheap, and then own a good 'Hot Hatch' car, and a great stereo. But sorry Geoff is not correct about a second part part, yes I do fully know the law of diminishing returns in the audio arena. I would say I am somewhat far up the price vs return on value ladder. (but only in a mid fi sort of way.. My one true Hi End expenditure, replacing 17 AC Duplex with Furutech GTX went OK, But that was just a one time momentary madness)And finally constraints.. In my head? No, they are on my bank balance.100% the bank balance.

I used my old Electraglide on my Oppo 105D made the picture better.

Yes, Elizabeth, you do dress expensive, your car and stereo..
Just don't eat too cheap, I mean low quality food and not low quantity of good food. Each time when I go to supermarket I feel a little uneasy because I usually buy quite expensive stuff compared to most other shoppers but not much of it so the bill is actually quite low.