I trail ride (as in...the kind you see in Washington State.) and I don't bother wasting my money on an expensive bike. None of the guys I know do either. We trash them too quickly! We just go and get the standard 200 dollar Mongooses' off the rack at Sears and put them together ourselves with a few custom parts. They last just as long as any other 500-2,500 bikes a few of my friends have wasted their time on getting.
I like this idea. A bike is a bunch of components, but when you buy one off the shelf, it is really two: the frame; and the "grupo" or component set. Frames made of similar material should be priced similarly. The grupos are only made by a few companies, until you get into more expensive stuff. If you have a good grupo and trash the frame, you can pull off the good components, put them on a new frame, and then you get to do it all again. You could take a frame left out in the rain or used by someone else and get a decent bike by doing this.