Sure for yachts and luxury cars the prices have barely changed

I'm not sure if that's actually true, but I'd note that for certain luxury goods, weird things happen with prices. You can wind up in a situation where higher prices make a good more-desirable because it's more-exclusive, more of a status symbol.

https://en.wikipedia.org/wiki/Veblen_good

A Veblen good is a type of luxury good, named after American economist Thorstein Veblen, for which the demand increases as the price increases, in apparent contradiction of the law of demand, resulting in an upward-sloping demand curve. The higher prices of Veblen goods may make them desirable as a status symbol in the practices of conspicuous consumption and conspicuous leisure.  A product may be a Veblen good because it is a positional good, something few others can own.

For luxuries like that, the price can be largely decoupled from the cost of production, and can instead be linked to ability to pay. Like, if the reason you're buying something is to show off that you can afford to pay the price, the cost of manufacture may not be what sets the price, even in a competitive market.

That being said, that's not all that common. It probably doesn't apply to whole classes of goods, but rather specific things like a brand (since if there's interest in the thing other than as a status symbol, competitors can produce a cheaper thing and find buyers). And the reason that it can be decoupled from the cost of production is only because the price is well above the cost of production.