When you buy online, you don't buy from a "dealer." Sure, you get an amazing price--because they buy thousands of machines at a time, and get a very good deal. However, you don't get classes. You don't have a service warranty. And there isn't someone to answer your questions. If you have a problem, it won't do much good to call Amazon.
It usually doesn't do much good to haggle over a price. The dealer has a price range they have to stay in, to keep their dealership. If they go below it, they could loose their dealership. You should get free classes and a service warranty -- like free service for the first year. Some dealers will add a percent off on anything bought with the machine. A lot of times, there are special financing deals -- like 36 months with no interest.
As a sewing machine mechanic, I look for a machine with the best stitch quality. As a consumer, some are looking for convenience and bells and whistles. The one thing that bugs me about the newer machines, is the forward/backward wiggle of the needle bar. One timing setting is the needle/hook distance. If your needle wiggles forward and backward, how can you control the needle/hook distance? You can't. So grab the needle bar and see if it wiggles. It has to wiggle side to side, but not forward/backward.
Good Luck with your purchase!