Royal 1d Black cover... Gustamps explains.

Gustamps say sometimes something really nice turns up on the philatelic market. Gustamps point out that occasionally such items end up in Her Majesty Queen, Elizabeth II's philatelic collection. Gustamps give an example: in 2001 a cover bearing several 1d Black stamps with First Day postmarks was purchased and included in the Royal philatelic collection. Gustamps say the price paid for the cover was £250,000. Gustamps added that this is only one of the many rare philatelic gems in HM Queen Elizabeth's stamp collection.