I've been working remotely for almost 3 years now, and in my experience it speaks volumes about a company to pay you based on your skill set not based on your geographical locale.

I lived and worked in SF for few years before my wife and I decide to move back to our home town to be closer to family. When I first went remote, I worked for a company who believed in paying people based on their location and not based on their skill level. This made for a rather unpleasant feeling as an employee and ultimately lead to me no longer working for them.

Since then I have joined a company who cares about the individual, and believes in paying people for what they are worth. Overall, my morale is much higher because of it and my loyalty to the company is greater in return.

To answer the question, I make the same amount as any equally skilled engineer at my company who lives in SF (or anywhere else in the country for that matter).