If they're willing, I would pay the seller to have the bike boxed and shipped to you, with the understanding that you have 48 hours to inspect and approve the bike. If it doesn't meet your approval for any reason, you box and ship it back at your expense.
This requires good communication via phone conversations, as well as sharing physical addresses and other personal information to guard against scams.
I've done a few expensive guitar deals this way, with zero complications.