Mosaic Records vinyl prices dropping

Has anybody noticed that the prices for used, OOP, Mosaic Records have seriously dropped in the last couple years? For example, Miles Live at the Plugged Nickle used to go for $500-$600. Now I see auctions that don't sell at $400. It's not just the Miles stuff, either. Any idea as to why? (It's possible I'm just remembering prices right before the 2008 crash.)

Is it the same with Mosaic digital stuff?