$50-$1000, depending on WHICH Ruger, and the condition it is in. Blued or stainless, what length barrel? . Sorry, but you did not give us enough info for a good answer- but get us some more, and we'll try.
500 USD each
100-300 or so
Zero. Ruger never made the P38.
100-300 USD
100-400 USD
100-400 US Dollar
0-300 USD
100-10000 USD depending on EXACTLY what you have.
Impossible to answer without a detailed description.
50-200 USD depending on condition
10-3000 USD depending on specifics
caliber 38 is a caliber 38. bullet dia. is .357 caliber deals with the dia. or measurement around the bullet head, not the bullet case.