I myself am new to the mountain bike world. I have always rode bmx stuffs, dirt jump, street and park. Just went to a mountain bike. I purchased a bran new Jamis trail x comp for 650$. I have been on this ride for a month and I like it but could have got a better deal on a used bike with better components. My advice. Get a bike that is your size, you are comfortable on and within your budget. The 2 best things on my bike are the hydro disk breaks and adjustable damper on the fork. Put some between your legs!