My advice...
#1. Buy a store. Not a bike. In your price range all the MAIN manufactures make a good and equal equipped bike.Find a shop that wants your business and is willing to work with and for you. By that I mean they will include a basic fitting. They will let you ride a few bikes and not rush you and will answer your questions nicely no matter how silly they may be. Look at frame warranties. Trek, Specialized and others will offer a lifetime frame warranty. See if they will offer a discount on accessory's which you will need.
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BMC Roadmachine
Kona Jake the Snake