I recently went into a Trek store here in San Diego to see about getting a bike to commute to work. It'll be about a 25 mile round trip. They fit me on a bike but the only bike I seemed to need was a Trek 7.5 FX which is a little more than I planned on spending. I had a budget set for 750.00. I then asked if there was something I could get to use both on/off road since they were a little bit cheaper and he directed me to the 8.4 DS and said it was the equivalent to the 7.5 FX. Is this true? Is he just trying to make more off of commission? What should I look for in a bike? He said this would be considered a long commute and steered me towards buying shorts for my commute along with shoes and everything else? I'm just not looking at getting ripped off. Thanks.