Go to a LBS that has the bike on the floor, bring cash and make sure you get a fitting. The bike shop Village cycle in Chicago sold me a Trek 520 for $200 less than MSR (It was on sale) and they gave me a hundred bucks of extra stuff, a custom fitting session and two free tune ups. I didn’t have to barter with these people at all, although I did ask if I could swap "this for that" and they had no problems doing so. I've spent around $1500 in that shop and don't regret a dime.
As a side note, my riding group likes to stop there when we do rides in the city. The guys in the shop will hold our bikes as we go eat lunch. We do buy stuff when we stop there. I think it's not getting a bad shop to bargan, but finding a good shop to give my money too.
Mike