[BS/MS or BS then MS???]

Do the combined degree and then apply for PhD programs. The PhD will (or at least ought to) be funded, so you won't have to worry about the cost, whereas most MS degrees are unfunded. In short, if you know you want a PhD, then make that your immediate goal.

Also, take advantage of research opportunities at your school and elsewhere; perhaps even consider taking a "research year" before launching into a PhD program. Statistics is a pretty meritocratic field (unlike, say, economics where it's all about the names), so theoretically you could go to a top grad school from a lesser known department.

[Stanford University]

It seems there a lot of MS Statistics people on this site. (I'm one too!) From North Carolina.

[Stanford Master's Results]

So who's attending?

[Stanford Master's Results]

Many schools have a policy of informing the accepted students first. As a fellow Stanford Statistics student, we should always recognize a "selection bias!"