I have a Winchester model 1885 in 50-90 Sharps and it's a Davidsons limited edition and only 125 were made. Should i use this rifle as a shooter or keep it unfired since so few were made and it may be worth more that way?

Here in Germany, guns aren´t at the moment and for the future a financial investment. So, I would say, "guns are made for shooting".
In the USA I mean, such typ of guns will never forbidden, so it would be logical, to save the rifle unfired............
But I would shoot the rifle. The curiosity would kill me.

Martin

Guns are worthless if you don't use them. Just useless pieces of steel and wood. The same as cash...worthless paper until it is spent.

The only way to measure the value is the enjoyment it brings from using it. A way to make money it isn't.

Since it is a modern reproduction I would not think it to have any special value or "collector" value. No doubt a fine rifle and desireable caliber, but as others mentioned, I would shoot it. If it is well kept, not marred and scratched, etc., you could still recover big percentage of your purchase price upon possible resale and also enjoyed using it. JMO