Even at today's higher gold price, beaten gold leaf is not particularly expensive. If there is maybe a tenth of a square inch area in the hot-stamp on a chip, the value of the gold would only be about a nickel. One of gold's interesting properties is that it can be beaten to VERY thin sheets. 1000 sheets contain only about 18 g. of gold. The foil not converted to lettering on the chip, of course, can be recycled with the supplier.

Not to say that modern chip makers do or should use gold for hot-stamping as the cheaper foils they use are fine for the purpose. But they could... without adding more than a few percent to the material in the chip.