It depends on who you ask. Some will simply say gold is gold or silver is silver. IMO, proof bullion is made for collectors who wish to pay a premium for it. The numismatic value is represented by what people are willing to pay over and above spot metal value. The big question is whether or not collectors will be able to recoup the premium later on. TC
Any coin commonly traded above face value and who's composition or metal that is traded above melt value has numistmatic value. That by definition is what numistmatic value is, it is by product of being desirable and collected. A multi-million minted common ASE can commonly be had at about a two bucks over melt, that is it's numistmatic value. Put one in a slab with an MS70 sticker on it and you have changed it's desirablity.
That's really how it can be put best. You may be in the room full of people that will only pay spot for a proof ASE. I personally do not pay a premium for graded or proof bullion. Others have an obsession with it.
