Yeah but even then it's not really true because it varies by location and I think NEVER was a little extreme. If you want pets it's fine. But you should be discerning and visit the farm to see if they're healthy or not before buying.
But for example, around here, wethers are usually like $125 or $150, which is below $200. And that includes registered goats from reputable breeders, good dairy lines, etc.
Bucks and does are well over $200, usually like $250 or $300 up to $350 or sometimes over $400 for really high quality ones, yes but wethers are cheaper and they're still perfectly good goats.
So again, I think it depends on location as well as gender so NEVER was a little extreme...
BUT.
It is a good guideline, especially for beginners, who might accidentally end up with a sick goat, so I think that's what was meant but still
And some people don't care about papers, doesn't necessarily make it quality. And around here sometimes even good breeders sell the mixed, unregistered, or lower quality animals for a lot less but they're still healthy