First of all, it seems like crutchfield is the store of choice on TW. Sounds like they have great service and can provide everything needed for an install.
With that said, I'm looking into getting the Pioneer AVH-P3400BH double din which crutchfield has listed at $399, amazon has it for $289. I know that crutchfield includes the wiring harnesses (at least I think they do) but I can get them from metra with the full dash kit at $45 for everything on eBay. I'll have to buy the steering wheel controls adapter as well either way.
What is the big advantage with going through crutchfield here? Saving 25% at amazon is big incentive.