I once read an interesting solution to this specific problem on the old Joel on Software forum. In addition to offering a competitive salary for people to work at an odd location, you could offer a relocation bonus for people to leave. This assuages a large concern that some folks might have: that they'd love to work at your company, but if things go sour, they'd be stuck in Pigs Knuckle, Arkansas without any other job opportunities. I'm sure there are wrinkles to iron out, but that would directly target a mostly unrealized objection to relocating to a less desirable area.