Related Clues:

• Done less?
• Harder to spot
• More eerie
• Not as likely to pop up
• More enticing to a philatelist, say
• More idiosyncratic
• More valuable, as coins
• More valued, in a way
• More valuable to collectors
• Farther out there
• More commonplace
• More puzzling
• More valuable, perhaps
• Not as numerous
• Less mundane