"Price fixing" occurs in the bike biz because manufacturers and distributors like having more than one customer. If word gets out that one retailer is selling their bikes for $100 less than every other store in the country, the other stores won't get much business, and probably won't order from the manufacturer anymore. If it keeps going on, they might get shafted out of selling things from other places too, and eventually you can only buy your parts from Performance or Nashbar.

Go to the LBS, and if you want a bargain, go used.