That's not how I think about it. The fundamental tools required to do your job aren't a perk, they are a necessity. If an employer skimps on the tools in a way that makes their employees less productive, then that is simply penny-wise/pound-foolish thinking from them. I'll use what I'm given at work; I'm certainly not going to spend my own money to buy a better work computer.

It's also true that I'm likely to leave a job that is so cheap they can't provide good computers to their employees, as if they're so short-sighted in that area they're likely bad in other areas as well.