Related Clues:

• Costly letter opener
• Treasure Island — finally shell-like
• Expensive honey
• Loved - costly
• Expensive - address
• Belonging to something nonhuman
• Subject for the Mark Twain Prize
• With 40-Across, a chorus line ... or a hint to this puzzle's theme
• Beloved — expensive
• Much loved
• Alternative to "honey" or "sugar"
• '-- in the bag!'
• "___ a done deal"
• TGIF's 'I'
• ". . . for what ___ worth"