I don't have actual proof of this, but I totally agree with the increase in the price. Last week I traded my vintage conch and vintage fan o' war for a headcase which at the time I thought was a great investment. However, 1 day later someone offered 6 buds for the two vintages.

Very narrow demand- I have a friend who collects solly items and even they haven't bothered to get one. I'll refrain from voting until I see more evidence.