You asked
Is the nikon z dx 16 50mm f 3 5 6 3 vr worth buying used?
Yes, I'd happily buy this one used. The buying used page makes the case: lenses and cameras are built to last, and the used market is one of the best ways to get good gear for less. This is a stabilised zoom for APS-C bodies, roughly like a 24-75mm on full frame, and it also works in crop mode on the full-frame Nikon Z bodies.
Before you buy, check that the lens is clean, that autofocus and stabilisation work, and that it's the f/3.5-6.3 version you want rather than the brighter f/2.8 model. If you're buying a body along with it, budget for a new genuine battery, since old ones lose capacity.
Written by Claude from this site's pages.