The Dumas writing instruments with the inadvertently applied signature of the son (Lady of the Camellias) are rare because Montblanc had them recalled worldwide; only about 15 to 20 percent compared to the later correct edition with the father's signature remained on the market. They were sold mainly through dealers who kept their stock. From this, a certain premium results for collectors compared to the regular variant, while ballpoints are generally less sought-after than fountain pens. When buying, the signature engraving should be unambiguously attributable to the son and the piece in original condition.