Paying remote workers differently solely depending on their zip code is immoral. If you can afford to hire from both San Francisco and St Louis, you can afford to pay both the same for the same work. If you can't afford SF rates, that's fine too! http://blairreeves.me/2020/05/22/paying-remote-employees-fairly/
Not every company is going to pay the highest salaries. That's why there's a curve! That's why we have percentiles! Pay the best rates your business can afford, but pay them uniformly. None of this lifestyle big-city subsidy bullshit. Same work, same pay.
Hell, you can even call it your patriotic duty! Distribute the spoils of the digital age further and broader than just a handful of coastal cities. Let that wealth flow into more and smaller communities. Whatever justification you need, just fucking get it done.