[Sponge5]

I'd say this is the perfect moment to quote Taleb:

"I've seen gluts not followed by shortages, but I've never seen a shortage not followed by a glut."

[Jiro]

I suggest you try buying some out of print blu-rays.

Often there's enough demand to make the cost of used copies go sky-high, but not enough demand to make a new print run profitable.

(This applies double to out of print video games.)

[dist-epoch]

Assuming demand is more or less constant.