A premium is the amount you pay above melt value. For bullion coins, that premium reflects fabrication, dealer margin, distribution friction, and current demand.
For commemoratives, premium behaves differently. Grade, mintage, theme, packaging, and auction visibility can all matter more than the raw metal content.
The right comparison is not just premium percentage. It is premium percentage plus liquidity, recent realized sales, and how easy the coin is to resell in the channel you care about.