The "thrust" [pardon the pun] was to try and get an idea of what cost would be associated with a space shot. If the cost was low enough, sub orbital, trans oceanic flight, could be accomplished in a very short time.
US to Sydney in 3 to 4 hrs?
If it is rockets all the way, any place on earth is 45 minutes from anyplace else, or less. You might want to land smoothly on the airstrip at Sidney rather than just make a crater near the terminal, so add some glide time, maybe 5 minutes. But the speed of SS1 is maybe Mach 5, and to be intercontinental would take well over Mach 15. That extra speed would require ten times the fuel and everything else is scaled up, too. It's a different animal.