We have collectors, and then we have shooters, and after that a lot of folks that fall somewhere between.
True collectables have a special value (or potential value) above an ordinary user, and especially if they are a classic or antique that were finished using a process that is no longer available, probably shouldn't be refinished if the owner has any intention of maintaining they're value, but to a degree it depends on how one wants to spend their money.
For example, in many cases you can buy an older gun that has 99% of the original finish intact, for less money then paying for a cosmetically distressed one - plus the cost of a top quality or original manufacturer refinish. If one is concerned about any real or potential collector's value they should sell the worn one they have, and use the proceeds plus refinishing cost to buy another one that has all the original finish to start with.
The advantage of getting an original manufacturer's refinish is that what really makes the difference is the way the parts are polished, and in many cases the gun maker has special custom-made polishing wheels that are shaped to exactly match the flats and contoures of the parts being polished. This is less likely to happen with those who refinish anything and everything.
But then we have those that want to upgrade a finish, say for a Colt Government Model .45 or a Detective Special or Diamondback that were originally finished in "Standard Blue," to a higher level "Royal Blue." Depending on what the particular gun is, the cost of the finer finish may come close to the present value of the gun, "as is," but if this floats your boat and you have the money to burn - have at it!
One should always keep in mind that if they plan to actively use a refinished gun it may not have that "new look" for long. This may or may not make a difference in one's thinking, but it should be a consideration. You may be spending a lot of cash to make it perfect, and then through use return it to what it was.
Concerning the S&W .44 Magnum currently under consideration. My course of action would depend on how much use I expected to give it. If it was to become an every-day user I would set aside the like-new stocks and wear some more of the original finish off. On the other hand if it would be an occasional user or be parked in a safe I would send it in to S&W to be checked over and refinished. If it was a common model 10 M&P .38 I would either leave it as it was, or settle for a new (inexpensive) bead-blast and Parkerize job.
But to each their own...