You asked
Is the 7artisans 35mm f 1 2 ii worth buying used?
I think it's a sensible used buy. The site describes it as a cheap, compact, fast normal lens for APS-C, so there's not much to gain by paying extra for a secondhand one. It's manual focus and not stabilised, so you're trading autofocus for a small, fast lens. If you like focusing by hand and want shallow depth of field for portraits or street, that's a fair trade.
Check the focus ring for smoothness and look over the glass before you pay, and buy from a seller who accepts returns. It fits many APS-C bodies, including the Fujifilm X-T30 II, the Sony a6400 and the Nikon Z50. For general advice, see buying used.
Written by Claude from this site's pages.