Ok so i recently have been looking to buy a pretty beginner bike. have been looking for used on craigslist with a budget of 300 to start off with to see how much i ride, how i like and so on. I am heavy set as well weighing 260, so looking for something strong. I am looking for a mountain bike, but nothing crazy. front suspension and disc brakes is what im after as well.I will be using it for road riding around town, and very light trail riding. maybe the bike park if i get brave enough but i doubt it. i am looking between a specialized hardrock, seeing what i can find of that used and a trek 3700 or something similar. i have found these so farhttp://seattle.craigslist.org/sno/bik/4420390472.htmland this one the guy will sell for 275 which i almost bought last nighthttp://bellingham.craigslist.org/bik/4427586786.htmlwhich is a better beginner bike? what else should i be looking for. and is the trek 3700 a good deal at 275?