Something everybody involved ought to understand before going too far down this road; you're not going to spread Silicon Valley prices all around the US and internationally. If you force the companies to pay a flat wage, you're going to get an averaging out at best, and nobody's going to be paid Silicon Valley's current wages.

Whether this is good or bad is beside my point, as are what other second-order effects may arise. I'm simply pointing out, "everybody in the world gets paid SV rates" simply isn't on the table. So don't go into this process expecting that outcome.