jg, these are great charts! You could remove the seasonal volatility in sales by plotting “percent change in sales year over year” instead of the absolute number. What would that look like?

Since the median price is a 1-2 year lagging indicator, it makes sense that your data would trail the median price by 2 years. Does the model show the early 90’s downturn, the late 90’s upturn, and August 2004 downturn?