It's hard to estimate, it depends on alot of factors, but I doubt it very much they'll rise anytime soon.
Alot of people have done solo buyouts recently (bringing a HUGE amount of JUNK into the game) Which has even lowered the price on disks / pumpkins & crowns recently.
Depends on if you'll be needing cash in the semi-near future. It is after all a discontinued item...therefore it will eventually go back up as there will never be more of these in circulation.
If you'll be needing the cash, sell it.
If you like it and are good on cash, keep it