See how much Slabbing helps your investment!
First, as Yoc said, congratulations. That's either a bargain or the end of a bubble. Either way...
Second, if we're coming to the end of slabbing utility, I see only one possible move: We need to start a collectibles market for the slabs themselves, and fast. I envision grading the plastic and then manufacturing a kind of "metaslab," where we encase the plastic case in plastic to preserve its (dubious) value.
But yeah, it goes to show that buying things for investment purposes, rather than for the enjoyment of the thing, is just gambling with gratification/payout deferred while tying up space.