hehe vaccum silver casting would do the trick
I think it offers very good resolution.
a big to-220 heatsink is 51gm, so you get something like 19cm3,
19cm3 of silver is 200gm, 106$
Now, how do you get the black anodized coating on silver (obviously a problem) to increase its performance like with Aluminum?
Given the price of a LT3080 is 6$ in single unit quantities, the heat sink price is slightly less absurd. Even more worth it for a LT3083 high grade part (11$+)

add the absurd cost of a stainless screw and thermal compound and it makes more sense
could aluminum plating the silver and anodizing the aluminum and dyeing it do the trick?