They'll consider it if they know someone else is willing to pay it. I got headhunted a couple years ago by a place willing to pay me 50% more than I made to work remotely doing generally the same thing I was already doing in-office. There were more responsibilities, though, so I wanted to stick with my current job if I could get them to match the offer. I took it to my boss, and he agreed to match the pay, and even talked the CEO into letting me work remotely when they otherwise have a pretty strong push toward in-office work.

Now I get paid more than my own supervisor while working a pretty cushy job in my pajamas.