In most cases you will be riding the bike you will buy. There is the chance they may not have the one you want in stock and you could ride a similar bike and then they order what you want. As for negotiating...depends on a few things...is it a 2013? you have a better chance getting big discounts if you find a shop with 2012 bikes still in stock. some shops sale bikes lower than MSRP already so talking them down on new bikes may or may not work. My LBS is a Cannondale dealer and they have very fair pricing. Which Cannondale are you looking at?