I currently have a Trek 4500.. my friend just bought a new stumpjumper, so he is selling his old hardrock. Is it worth buying ? Maybe to transplant some parts to one or the other.. or just use one as a backup bike? If so, what would you guys consider a decent price? Wondering if it's worth it, or just save up for a new bike altogether. From what I understand I don't think the hardrock has anything spectacular compared to the 4500 that would make me want to buy it now. Opinions anyone? Thanks!