The premium is determined by grade and mintage. Rare coins in a high grade command high prices. An 1893-S Morgan in AU50 will fetch six figures at auction. An 1878-S Morgan in AU50 is worth its weight in silver plus a couple of dollars but an 1878-S Morgan in MS68 will fetch substantially more.Collector prices are probably lagging well behind the quickly rising "junk gold" price-by-weight.
A "collector's coin" would be worth its weight in gold, plus a premium for being a collectible coin.