About $300, depending on exact version and condition.
No. The 44 Magnum cartridge is too long to fit a .44 Special firearm- and it is loaded much hotter than the .44 Special- unsafe to attempt. .44 Special CAN be safely fired from a .44 Magnum firearm, but not vice versa.
about 3200 dollars.
None of my references show a .44 Special Blackhawk- 44 Magnum yes, 44 Special, no. The .44 Magnum Blackhawk is about $450-550, depending on condition. The FLATOP version is worth significantly more.
Depends on who did the engraving, and if the pistol has ever been fired
Yes. The 44 special is a bit shorter than the 44 magnum, so it will fit in the cylinder of the 44 mag. The reverse won't work, however. A 44 mag cannot be fired in a revolver chambered for the 44 special because the 44 mag is too long and won't fit in the cylinder of the 44 special.
50-250 USD
there is no 45 pistol, however there is a 44 pistol. the 44 pistol can be found as random loot or off the corpse of someone with a 44 pistol.
No serial number given.
75-300 USD or so
10 USD or so
50-2500 usd