Experiment by riding fast and slow, by making gentle and sharp turns. Try out all the gears as well as the brakes. If you're not satisfied, keep looking - and test riding. Some shops offer services, such as a year's worth of tune-ups, that in the end will save you more money than a discount on the price. Your shop may offer other services, too, like a layaway plan.
Some people buy bicycles with only the present in mind.
If money comes easily to you, that's fine. But if shelling out a few hundred dollars isn't a regular occurrence for you, you should probably think about the future, as well. Many people buy bikes with unrealistic plans. Be realistic about your cycling goals and what you really need to reach them. If the price sounds too good to be true, it probably is.