Look for coins with a "Deep Cameo" (DCAM) effect—a sharp contrast between frosty designs and mirror-like backgrounds. These can command much higher prices when professionally graded. Where to Buy Proof Sets

Never clean your coins. Even a soft cloth can create microscopic scratches on proof surfaces that "tank" their market value.

Sets should remain in their original plastic lenses and boxes with the Certificate of Authenticity (COA). Breaking the seal can reduce value by 20% to 50%.

: Notable for its low mintage, currently valued significantly higher than its $68 release price. What to Look for When Buying