Flux core solder for electronics

The cheap stuff doesn't stick to the things you're trying to solder. The good stuff melts and flows into the joint like magic. It's really satisfying.

Toilet paper.

It used to be headphones but the stuff in recent years out of China is so good on sound quality. You can get what used to cost over $1000 USD for < $350 with great stuff @ $150 & even servicable stuff @ $20 for a spare.

GPU's, usually the budget ones have worse performance per dollar ratios

I would argue blenders/mixers aren't on that list. Used my mothers fancy one, used fancy ones at school, used friends fancy devices. And used my rubbish $12 blender from BigW, so I do not see why anyone pays more than $12 for a mixer ever.

Boots, though, shoes, headphones, and laptop. Those are good to be quality.

OLED tv

Windshield wipers (that don't go SQUEEAK SQUEEAK & actually let you see out the window).

Nothing. I always pick the mid-range products