One of the absolute sickest TVs on the market (click it):
VISIONS
It's a 55" at $4199 (Best Buy) but I guarantee you can scoop it for much less if you buy something else. Hell, I bet you they would almost throw in the warranty.
I used to be the Home Theatre Supervisor at Best Buy, and let me tell you... as long as you express interest in the warranty they will give you a sweet freaking deal.
What I would do, is get the sales person to tell you what you need (cables, warranty, whatever else you want) and come back with a quote. Then take that quote, let's say it's $5000, and tell them you need to squeek under $4000 and they will do everything they can to close it.
The margins on these TV's is usually around 20%. Therefore, a $5000 TV only costs them $4000.