It's one of those things, where if you have to ask "How Much" you can't afford it. There was another one in an article in Shooting Times magazine many years ago. It was in a New York collection. The author and owner took it to a range, with controlled ammunition, that was hand loaded to mil spec for trials and each fired a mag full through it. The pistol was insured for $1million. I guess the economy has brought prices down sharply.
The Chinese were going to build some in 45 acp. I never followed up on whether they did or not.