He has a quick look around.
There is a little loot but none of it readily exchangeable for US dollars, the principal currency in which plane tickets are sold.
Eh, you can always find somebody. Miles pockets some likely-looking objects. "Okay, let's go."
So she drives him back to Sunnydale and drops him off by the butcher shop.
And he hangs out with Zeke and commits petty theft and decides to scrap the whole idea of buying a plane ticket because faking the necessary identity documentation would require too much human contact and stowing away in a luggage compartment is safer. This still requires him to acquaint himself with flight schedules and pick up supplies, though. And he'll need some means of transporting himself to an airport...
He loiters by the butcher's shop around sundown; when Bella doesn't happen by, he tries the school.
Not in the library, or anywhere else in evidence on campus.
Bella, meanwhile, is waking up on a truly unpleasant floor, even as floors go.
She manages it eventually.
She tries the door. Locked. She tries to stand. No such luck. She tries a window. Painted shut.
A familiar figure emerges from the shadows. Although he's wearing different clothes, blander and less crisply military than the grey-and-white Dendarii uniform.
"Miles," she says in relieved confusion. "Where the fuck are we?"
"You've got to be kidding me," says the familiar figure in a decidedly un-Miles-like accent and cadence.
"Sorry. Mark," he says, with an ironic little bow. "Miles's twin. He may not have mentioned me. I represent a particularly awkward and private chapter in the family history."
"Yeah, I'm not surprised. So, who are you and why are you sitting on the floor of this horrible little house drugged into near-paralysis?"
"Uh, my name's Bella and I am not entirely sure but I don't like it. Why are you lurking in this horrible little house?"