50-350 USD or so
No such weapon exists. Ruger made a GP 100, but Beretta never did.
50-300 USD or so
100-400 US dollars.
400
The weight of a Ruger GP100 must be 2.2 pounds, 76mm barrel length, and is double action. It has a range of 55-110 yards, and can be a 6-shot or 7-shot gun.
It will accept 357 magnum or 38 special ammunition.
In wash. State, I paid $425 for a used 6" stainless and the local pawn shop pays $375 for a good used one. If you can find one, never sell it. These are quality pieces.
About $600.00
50-450 usd
The GP100 is a great revolver, but if you're backpacking in Alaska - where you could be subject to encountering bear - you would definitely much rather have the .454 Casull.
No such model exists. The .357 Magnum cartridge was not put into production until 1935, and Ruger was not established until 1949.