Price, always affect the perception of value. You can see this very often in Amazon, where the same razor, is sold rebranded with 4 different brands, ranging from 8 to 30 EUR. You read the opinion of the guy who bought the 30 EUR rebranded version and he mentions "excellent quality, excellent value to price ratio!". You go read the review of the same razor at 8 EUR and you see "well, for 8 EUR one can't complain. It's a cheap chinese razor, but works well".
Same thing easily goes for brushes. Badgers, especially when you start, are automatically "soooo much better", since the "boars are cheap". "I started with a 10$ Omega, so now i want to go to a decent badger brush". It's no coincidence that wetshavers that abbandon badgers for boars, are seasoned wetshavers that after trying and paying for every famous badger out there, decided that the cheap boar wasn't that bad after all. If boars were as rare as badgers, boar brushes would also be more expensive. Luckily for some of us, pigs are common.
This said, there is the law of diminishing returns in all products, but, in hobbies or collectors, it usually isn't about wetshaving so much, as is about the thrill of adding "one more to the collection" or "have a more prestigious brush". Emotional satisfaction, adds value to the object and also boosts physical satisfaction too.