You asked
Is the panasonic lumix s 18mm f 1 8 worth buying used?
Yes, I'd call this a good used buy. Lenses hold their value far better than bodies, so a used copy costs you less to own over time, and if 18mm turns out not to suit you, it's easy to sell on. I can't tell you current used prices, so check listings yourself. The buying used page covers how to shop, and its what holds its value section makes the case.
It's a full frame L-Mount prime at f/1.8 with autofocus but no stabilisation. That makes it a good wide, bright option for landscapes, interiors and street work. It fits a long list of L-Mount bodies, including the Panasonic Lumix S5 II, the Panasonic Lumix S1R II and the Leica SL3. Check the full details on the lens page before you buy.
Written by Claude from this site's pages.