Sounds like my wardrobe.
I had exactly one brown suit and one brown blazer, among the several suits and blazers I wore when working or attending church. I still had the nickname, Mister Brown.
Same here - Comfortably "broke-in" jeans and T-shirts and sneakers that range from "gonna use one last time on a dirty job" to "less than a year old dressy occasions".
Not sure using change for purchases will protect anyone - those that will rob/kill you for ten bucks will do the same for ten cents if it increases what they have. Being well armed and situationally aware while limiting exposure is probably the best bet. Having a partner so you can watch each other's backs would also be handy.