These are absolutely gorgeous guns from the Colt Custom Shop. They are currently in production and have been so for a couple of years now (my earliest Colt catalog that features it is 1992). I've seen asking prices of ~$1,100 to $1,400 for NIB guns.
There were a couple of variations too; I don't know if any particular model/version commands more. Colt offered regular and "carry" versions and now they're offering them in .38Super. I've seen them in blue ("carry"), satin nickel/blue and hard chrome. Older ones have double diamond blackwood stocks w/ the Colt medallion, current ones have double diamond rosewood stocks w/o the medallion.