If you want to pay 15% over the actual value of the metal contained in the coin, rock on.
TY but where would you buy the actual coin for its say KITCO value?
US numismatics are pretty much the be all and end all of coin collecting. That is mainly due to the fact we have excellent mint records and a span of types and mintages that it’s possible to complete.
Numismatic value is determined by the difficulty and popularity of completing sets. Rarities end up being driven up within and outside the community.
For instance take Lincoln wheat cents and Indian head cents. It’s a lot easier to complete a set of Lincoln wheat cents than an Indian set, so even though the 1909-S (S= San Francisco) Indian head is rarer it doesn’t command as much as the 1909-S, V.D.B. (Victor David Brenner, designer) because that’s a key rarity for a set completable by a larger segment of the population.
Numismatics purely from the standpoint of a sales guy saying “this goes up a lot” is definitely bunk, but if you understand the hobby, and the historical associations, the right coins almost never lose their nominal collectors desire value unless a large quantity of high grade lost ones turn up.