The decision you make about it, more than anything intrinsic. A user knife is sharpened, carried and maintained, and its value is in what it does. A collector knife is kept unused, unsharpened and boxed, and its value depends on staying that way. The same model can be either; it cannot be both.
Everything that makes a knife a good user, being carried, sharpened and worn in, is exactly what removes collectible value. Every sharpening moves the edge back, every day in a pocket wears the bolsters, and neither is reversible.
People who try to have it both ways generally end up with a knife they are anxious about using and which has lost value anyway.
Make the call before the knife arrives, not after you have carried it for a month. If it is a user, sharpen it properly, carry it, and enjoy it. If it is a collectible, leave the edge alone, keep the box and store it well.
Buying two of a knife you love, one to use and one to keep, is the common solution among collectors.
Most of what we stock is built to be used. Some pieces, particularly in Licensed & Movie, lean display rather than working.
The product specification will tell you which. See are replica knives meant to be used.