If you insist on going new stick with Trek/Specialized, they are by far the most value due to the sheer volume of their company sales.
I beg you to watch Craigslist for a month or two, you will get an absolute steal if you know what to look for and jump on deals. Many men who spent much more are dumping the bike they have ridden a handful of times. I picked up a $2k new specialized for $350 from the widow of a man who bought it years ago but died of a heart attack, the bike still had the tiny rubber rods that stick out on the edge.
Also for the riding you are going to be doing I would aim for a lightweight hardtail, you can get an epic hardtail on CL in your range if you look hard enough.