I am in the market for an entry-level bike. I will be doing mostly paved path riding with occasional dirt trails. I will be jumping stuff and riding it pretty hard. I have looked at the Giant Rincon, Giant Boulder and SE, Raleigh M40, 2004 Raleigh M50 and a Jamis Cross Country 2.0. Which of these bikes would be better and last longer. All of these bikes are in the range that I am looking to spend. Are any of these significantly better than another? Or I have the opportunity to buy a month old Trek 4300 for $275.