No, they do not use the same magazines.
The Ruger SR9 uses a proprietary magazine.
It doesn't.
Try e-gunparts.com or Mec Gar
I paid $439 for mine at Outdoor World. MSRP is 525
Can't be answered without a DETAILED description of ALL markings, to include label on box.
I have seen very few used SR9 Rugers at my local gun shops. However you can buy a brand new one for around $360.00. That is a pretty good deal if they get some of the bugs worked out.
From the Ruger website: What type of ammunition should I use in my Ruger 9mm pistol? The Ruger 9mm pistols are chambered for the 9x19mm NATO Parabellum (9mm Luger) cartridge, compatible with the U.S. and foreign military or commercial 9x19mm loads manufactured in accordance with NATO, U.S., SAAMI, or CIP standards, including high-velocity, subsonic, tracer, hollow point, ammunition loaded in aluminum, steel, or brass cartridge cases, +P and +P+ ammunition.
The Ruger 9 mm Model 94 is not a commonly referenced firearm, as Ruger is better known for models like the SR9 or the P-Series in 9 mm. If you meant a different model, please clarify. The value of any firearm can vary greatly depending on factors such as condition, rarity, and market demand, typically ranging from a few hundred to over a thousand dollars. For an accurate valuation, it's best to consult recent sales data or a firearms appraiser.
Depends entirely on which 357, and the condition of both guns. Some are worth more, some less.