I bought one at auction for $150
Depending on who made it and its condition; 100-1000 USD
20-60
38 special is only a revolver caliber. that's like saying a 44 magnum revolver or a 500 special revolver. a revolver is a revolver
10-1000 USD depending on specifics.
25-50 USD or so
40 or so
It depends on what you mean. A .38 revolver may be a .38 special, but there are other types of .38 besides just the special round.
50-500 usd
50-500 usd
No
A ".38 +P revolver" is simply a .38 Special revolver which is rated to fire +P loads. It's still a .38 Special, and the +P doesn't change the dimensions of the round itself.