Mountain Bike Riders, Question

The folks that recommended used are steering you correctly. You have received good advice. You will want to find a large or probably extra large framed bike for sure. Stay with the rear hardtail for cost and the weight penalty of a rear suspension. You should be able to find a decent used bike for 3-500. Stay with the true bike shop brands (even though they are almost all made by a few Asian factories these days). Shimano or Sram are fine and the lower levels of componentry have really improved over the last several years but if you can find the better componentry it will be a plus even if it's several years old. Most important is finding a bike large enough that you will be comfortable on it. Schedule yourself a committed time to ride once you get it and you will be glad you got it.

If you run out of used options this link could be an option for new. http://www.bikesdirect.com/products/mountain_bikes.htm