There have been a few videos by hardware reviewers to address the sample size concern. Gamers Nexus tested 3 different CPU models with 20+ CPUs each and found that the biggest variance from lowest to highest performance was under 4% while performance variance in most cases was about 2%
https://www.youtube.com/watch?v=PUeZQ3pky-w
The way CPU manufacturing and binning are done means that cpus in particular will have very minor differences within the same model number.
I started with a $15 double edge safety razor that I used for years. I bought the $70 Henson razor because I wanted a better shave, but the results are about the same as the $15 razor I started with. The Henson razor glides better so I can get the same quality shave with less time. I can also shave twice (one across the grain once against) if I want a better shave, but it still isn’t the smooth shave I was hoping for. The henson razor came with 100 blades, but you can also get 100 blades for $10 on amazon.