Free computer operating systems are great these days.

I regularly spend hours designing electronics to be cheaper. Not worse -- just cheaper. Electronic components sometimes vary in price by two orders of magnitude for the same performance, so it's worth cramming datasheets in your head as a professional or hobbyist.

For tools, I've found good midrange Chinese brands, and stuck to them. I could never afford things like Tektronix and so on.

I don't strictly require clothing to be cheap, but I do require it to be fungible -- this works out similarly though. When I find something that's good value for money and looks good, I buy a bunch and rotate them. That way I don't have to think about what to wear, and it always looks decent.

I also prefer cheap laptops. I don't need a supercomputer to work. When I do need a supercomputer, I rent one from google cloud for a few dollars an hour.