Many, many people (especially sellers) confuse firearms that are meant to Honor or Commemorate an event or agency with firearms that are Collectible.
There is a reason that we have two different words in the dictionary . . . Commemorative and Collectible.
Some Commemoratives achieve collectible status over time. The FBI Model 27 and the Texas Range Model 19 are both highly sought after by many Collectors
I happen to like many Commemoratives, especially those that have extra embellishments like the Deluxe Texas Ranger or the Deluxe Texas Sesquicentennial Commemorative
Most of the value of the revolvers pictured above exists because of their special embellishments, not because of what they Commemorate
As to Commemeratives that do not carry unusual embellishments, if in unfired condition, they will sometimes bring a premium over a similar model if you happen upon a person that admires what is being commemorated. However those firearms usually sell for what a good used example of that model will sell for or sometimes even less. For example the Chicago PD Model 66 that Jughed440 mentions above
Once you start shooting a Commemorative, then it is just another shooter (unless it is highly embellished), even to those that would have paid a premium for it because they admire or were part of what is being commemorated