You asked
Is the ttartisan apo m 35mm f 2 asph worth it?
Worth it if you already shoot a Leica M. This is a manual-focus, full-frame 35mm f/2 prime for the Leica M mount, and it fits a long run of M bodies, from the M9 through the M11 range. If you don't have an M body, it's a poor fit, because the mount is the whole point.
If you do shoot M, a 35mm is a good everyday focal length for street, travel, and documentary work, and f/2 gives you useful low-light speed. The site doesn't list a price, so I can't judge value for money. Check the current price yourself. For the broader choice of focal length, see your first lenses. On full frame, a fast prime is one of the best things you can buy, as explained in sensor sizes.
Written by Claude from this site's pages.