When the economy takes a downturn due to recession or depression, collectibles are one of the first things to decline in value, and one of the last to come back when recovery is taking place. It is fairly easy to quit purchasing collectibles as times get hard and it takes a while after recovery begins to catch up and get to the point of having disposable income to spend on your hobby.
Investment quality collectibles usually regain their value and actually outpace previous values. The bottom end of the market in collectibles often times does not recover and remains below previous values.
The economy is doing pretty well right now and hopefully we will see a good recovery in our collectibles value in the near future.