This is one of those things I don't argue with people about, but I started running around 1971, and get good quality running shoes. I currently use Nikes, but have also used Saucony, New Balance and Converse (back when they made a running shoe.
I wear them until they're worn out, but always get good quality. For one thing, the Walmart brands have more plastic in them and start smelling. They also feel more rigid. I'm usually either in running shoes, Hi Tech Magnums or firefighting boots.
I started running in the early 70s too, but only in the spring to get ready for softball season. I also played tennis back then. Then Labor Day weekend 1981 rolled around, I quit smoking and started running.
You're a firefighter in southern California. Wow, my hat's off to you - I'll bet you have a few stories to tell.