Uh, blue collar clothes. Shit ain't cheap though. Duluth Trading, Carhartt, 5.11, etc...

Duluth I know has stretchy denim. Meant for comfort but it helps with minor weight changes.

Become (more?) familiar with the needle and thread. Things can last a long time when they need to.

To make your clothes last longer:

• Buy natural fibers instead of polyester, they take heating and bending a lot better than plastic

• Wash cold and without bleach unless otherwise necessary, both cause more wear on the clothes. Fabric softeners are also not great and will make your clothing less absorbent, which is miserable when you’re sweaty

• Dry in a dryer minimally if you can avoid it, they’re very rough on clothes. And no dryer sheets, that’s just coating your fabrics in oils

• Inspect and repair small tears before they become big tears. Patch big tears before it falls apart

You don’t have to do everything on the list to get good returns on longevity, I always use a dryer have a few 20ish year old shirts that are just now coming to the end of their lifespan from being worn to death.

Walmart. I'm just careful with my clothes, use cold water and gentle cycles