I would recommend going to a bike shop and riding several different styles of bikes. Until you find out whether you prefer the upright position of a mountain bike, or the leaned forward position of a road bike it's hard to recommend a particular bike for you. I would suggest going to a different shop as well, there are many many brands out there besides trek that make different style bikes with different geometry.

It's like asking us what kind of car you should buy without telling us whether you need an suv, pickup truck, or compact. There are tons of choices with many different styles that will fall into your budget, so its not a question of money; it's a question of which bike is right for you, and if you don't know the answer then you should go to the bike shop and tell them you would like to test ride bikes from different categories.