There is a starting point for the Korean series. The references are in place, there is a rarity scale and a market both inside and outside Korea. That market last “boomed” in the 1990s. Prices, except at the top end, have had to be reasonable to get them to sell, but inventory is not so easy to obtain, rare things are hard to find. Imitations and fakes of Korean coins are not so common, but modern versions of old amulets are.