Related Clues:

• Most valuable, perhaps
• Least likely to be spotted
• Hardest to find
• Most seldom seen
• Least likely
• Hardest to come by
• Like a numismatist's greatest treasure
• Most like a collectible
• Most frugal
• Most in the raw
• Most difficult to find
• Least plentiful
• Most meager
• Least generous
• Most uncommon