Many dealers carry the same stuff as everybody else, and try to gouge you for special orders. Besides this stuff, I'm curious of what you've seen dealers do that is shady, deceptive, and/or jerky.
I haven't been the target of any shady dealer tricks yet. Then again, when I'm ready to buy a gun, I've already researched it as much as possible. The trip to the shop is mainly to check fit, handle the gun, and make sure it suits me.
My local shop is fantastic though. They don't charge extra for special orders and even help you deal with the manufacturer for issues related to guns you didn't buy from them. The worst I can say about them is that their ammo is a bit high. It's not really an issue for me since I handload nearly everything I shoot.
Chris