While I think there is some correlation with gear between cost and quality, I also think it is a case of diminishing returns. Plus, on the high-end gear, you sometimes pay a premium for newer technology materials (that my not even be thoroughly tested).
I tend to stick with the midrange gear (Olympia, Firstgear, Tourmaster). There's always great gear for sale at the internet closeout places (motorcyclesuperstore.com, motorcyclegear.com, motocycleclosouts, etc, etc). I paid $130 for my FG Rainier, and $150 for my Olympia Bushwacker. The 2010 version of the Rainier can be found under $200. The Tourmaster Transition2 can be found under $150.
I've owned BMW and Rev'It gear, but don't find it is worth the upcharge (for me). But there certainly is A LOT of used, high-end gear for sale for great prices - much of it barely used. In fact, I sold off the gear I was no longer using on ADVRider (Rev'It and Olympia jackets, BMW pants, and a couple helmets). That being said, although I've seen several bargains there, I also see people paying a lot for used gear. For me, if buying used from an unknown source/internet, I expect to pay about 50% for gear in very good shape. Otherwise it isn't worth the risk or the hassle if it doesn't meet expectations. However, all my transactions buying and selling on ADVRider have been flawless. So I think it is a pretty trustworthy pool if dealing with established members.