High end, high price goods classed as exclusive aren't manufactured in the millions like cheap Primark tshirts and jeans.
The highest quality material is sourced, a designer has to be paid. The goods will be hand finished and minutely inspected. Any fault and the item is scrapped, not sold as 'second' or 'reject'.
Add on the very high costs of advertising. They're not advertised in the Sun or the back pages of TV Quick.
If a person wants to pay £3k for a handbag, that's fine by me. There are plenty of adequate bags available in the sub £20 price bracket.
As for gold that is a high demand item world wide. It's world markets that keep the price high and you can be sure the price will go down. It always does.
Anyway, if it were as cheap as stainless steel nobody would want it as jewellery. It is also used in medicine, electronics and it's even used on the visors of spacemen's helmets.
We are fortunate that we can get most necessities at a reasonable price but if you want to pay for labels the choice is out there.