[berberous]

There are many art forgers that have cranked out fakes that have fooled many art experts, i.e. they are truly indistinguishable. And yet, their value, once discovered to be a fake, is negligible next to the cost of the "original". So no, most of the value (at least to the market, maybe not you personally) is not in the technical quality, but in the provenance -- in that it's the "original".

[dogma1138]

That’s because they are forgeries, a good reproduction costs a lot of money, not as much as the original but it’s quite common to commission reproduction copies of famous paintings ones that will use period materials and techniques can cost a small fortune on their own.

This is also very common with statues that are even more expensive due to the materials and labor cost, a good copy of say David that isn’t a cast can cost high six figures easily.