The answer is, it depends.
Ultimately, all the materials used will do is create a base line of "value" for
those materials ability to be reused.
For the initial object the cost will be higher because you need to pay for
the designers time. Additional copies or the right to exclusivity will effect
the price since the design cost is spread out.
With regards to materials, you are dealing with a completely separate
issue. Jewelry sells for much more than the "melt" value of the raw materials.
"Value" will vary depending on the perception of the potential buyers
more than the mere materials. Consider a Baseball card. One with a
popular player sells for much more than one of someone of less
popularity even though the materials used to create those cards are
identical.
Likewise, the same applies to the art world. People pay quite a bit
for ordinary materials used in "new" ways. Personally, it seems
stupid to me, but that's not relevant.
Yes, in all likelihood the one made from gold will sell for more than
the one made from silver, given the exact same design and print runs.
But if the silver one is a proto-type of extreme limited edition it may
in fact sell for more than the gold, provided there are 2 sufficiently
monied collectors willing to fight over it.
Some guy spent, I think, $50,000 for a sealed copy of a Nintendo
game that was rare simply because it was so terrible that no one
wanted it at the time and thus became rare since they were made in
limited quantities and the unsellable remaining pieces thrown away.
