You don't get paid based off your expenses. You get paid the minimum your employer thinks they can pay to get someone who does the job well. I'm not disagreeing with you, but this argument will get you nowhere.
(speaking from experience as someone who undercuts themselves a lot)
Very true. Most of us also aren’t paid for the value we produce. We get paid for the replacement cost.
So let's talk about how it can be a valid argument, instead.
Employees expense computer equipment, cell phone bills, gas, car rentals, hotels, and more. I don't view this differently.
I'm working from my bedroom, we're already short on bedroom space; I'll gladly work from home for a fraction of what my employer pays to accommodate me in an office. But I probably wouldn't have taken this job knowing I'd be stuck in my bedroom 18 hours a day.