I'd refinish a gun as a retirement gift . . . to the gun.
A gun that is still in use will soon be a worn, refinished gun rather than a worn, original gun.
I had a welding repair done to a blued gun that resulted in some mottling from the heat and spot-reblue, so I did some dehorning and contouring, and will have it refinished, so that it has a finish.
Shipping alone, for a handgun, is about $100, so I'm looking for a local place to do the work.
Bluing, which seemed to be offered by every gunsmith 20-30 years ago, is now very hard to find, and the spray-on finishes have all but replaced it.
For a gun that is going to continue to see regular use, for a refinish I'd suggest hard chrome, if you like bright guns, or Ionbond, if you like dark.
Both finishes are extremely hard, wear resistant, and look good.
Unlike most other finishes, other than bluing, plating and Ionbond can be applied over polished surfaces, so you don't have to go for a matte, "tactical" look.