You asked
Is the viltrox af 25mm f 1 7 air worth buying used?
Yes, I'd buy this one used if you can. The Viltrox AF 25mm f/1.7 Air is a cheap, light standard prime for APS-C, and it's an easy lens to buy second-hand. Lenses are built to last, and used gear is one of the best ways to afford good kit. On an APS-C body it frames like roughly 38mm on full frame, which suits everyday shooting well.
It's made for Sony E, Fujifilm X and Nikon Z mounts. It has autofocus but no stabilisation, so it's worth weighing that up if you shoot handheld in dim light. For what to check before you buy used, see buying used.
Written by Claude from this site's pages.