https://www.hagerty.com/articles-videos/articles/2019/02/15/1986-89-mercedes-benz-560sl-ready-to-rebound -- The collector car market isn’t anything more than supply and demand. Simply, there are a lot of 560SLs out there, many of which have low miles and demand has slowed down so the prices have dipped. The next question is why has demand slowed? Any increase in prices without a change in the amount of supply, but instead with only a change in demand because of an increase of perceived collectibility is the epitome of a bubble. That’s what happened here, with Porsche 993s, Ferrari Daytonas and many many others. Limited cars, or configurations, or very low miles are really the only ways to buy cars knowing the prices are unlikely to dip, or at least are going to continue to appreciate.