with 27.5" wheels being the hot new thing, i'm guessing pinkbike will have a flood of perfectly good 26" wheeled DH bikes in a few months as people start to build up new rigs. I paid $1200 for my DH bike, which has a 7 year old frame, but all the other components were brand new. It was a calculated gamble which, I think, should pay off well by being able to snag a much newer used frame for pretty cheap. I'd argue that it's tough to get a "bad" DH frame. Sure, different brands use different suspension setups, which all ride differently, but one isn't really worse than another. Wheels and brakes are the two areas where I'd say it's worth making sure you've got solid components. Your wheels will take a bunch of abuse, and especially while you're new to the sport, a set of XC or AM wheels is not going to stand up to the abuse. As for brakes, you want to be able to stop as quickly and safely as possible when needed. Saints, Zees, Codes, or really any other 4-piston brake would be something I'd definitely look for in a DH bike. Without knowing more about your riding style or preferences, it's pretty hard to recommend any sort of suspension setup or brand.