I’ve spent years shooting M-mounts and honestly, I’ve seen cameras ruined by cheap cases that trap moisture. In my experience, you need vegetable-tanned leather for an M6 cuz it breathes and wont mess with the finish. The Kaza Deluxe Leather Half Case for Leica M6 is the absolute sweet spot for a $150 budget. It uses high-grade cowhide and the stitching is reinforced at the lugs. I’ve dropped my M4 in one of these and the leather absorbed the impact perfectly, ngl. If you want something stiffer, the TP Original Leather Half Case for Leica M6 uses Columbia cowhide with a built-in metal base plate. That base plate is key for impact resistance on the bottom plate where the M6 is most vulnerable... kinda essential for the subway. TL;DR: Grab the Kaza Deluxe Leather Half Case for Leica M6 for quality leather or the TP Original Leather Half Case for Leica M6 for the reinforced base. Both ship fast.

Unfortunately, many high-end leather cases are not as good as expected given their insane price tags. I have had issues with fit and finish on boutique brands before. Since you are in NYC and need it fast, look at the Funper Leather Half Case for Leica M6. It is a cost-effective choice that provides solid protection for subway commutes. It is not a masterpiece, but it gets the job done for way less than $150.

This ^

Building on the earlier suggestion, Kaza is solid but I’ve been super satisfied with my TP Original Leather Half Case for Leica M6. It’s well under your 150 budget and actually feels like real leather, not that plasticky junk. Best part is the opening for the battery and film loading... saves so much time. It’s handled my daily commute without a single scratch on the baseplate yet.