My apologies about the Doctor comment, Just sorta touched a very raw nerve.(pun intended)
That said, I have seen the same thing in the collector car trade, particularly certain high end makes, like Ferrari. The "investors" took control of the market in the late 80's and drove the prices out of sight. Then the market crashed and the one time $180,000 BB512s were being sold in the high 90's and low 100's.
I feel that any time "investors" begin getting involved in a market that was once the pervue of true collectors that the volitility occurs as well as pricing going up so high as to make the regular guy get out. Kinda sad really.
