It is my understanding that the LBS does not make much money selling bicycles. They make money on their repair and maintenance work on bikes and on clothes and accessories. So the LBS has pretty limited ability to "deal" because they don't have much mark up. Where you may be able to get benefits are on things like service. Most bike shops will let you test ride a bike. They will fit the bike to you. You can usually get them to put a stem on the bike to optomize your fit. You might be able to get them to swap out some parts on it.