Buffy says, "Get out of the basement." Spike says, "I don't have anywhere else to go." The spoiled among us know where he really ends up, but let us for the moment suppose that ain't so. Buffy puts him on a bus to L.A. -- with orders to find the one vampire she knows has experience at dealing with a soul.
Only of course that one vampire is in Las Vegas, being a wince-inducing, name-dropping, pain in the ass. But hell yes, Wesley will take his clients while he's out of town.
It just sort of fizzles when I get to the part about what they'd actually *do* with each other. Esp. with Lilah around as a complication.