Well, I know a handful of vintage trials and MX guys. And if there's one thing I can say for certain its that they spend money. These are the dudes that owned these bikes when they were kids back in the day. Now they're nearing or at retirement age, and most have plenty of expendable cash that they use to buy the toys of their youth.
My point is... If you can buy it for $150, do it. Play your cards right and find the guys who NEED this stuff and you could make a few bucks. No doubt.