Friends of ours have just rediscovered a boxed bottle of Dom Perignon 1993 that they were given as a present a while back. They are never going to do anything with it so were thinking of selling it and giving the money to the orphanage in Uganda that they support.
The seal hasn’t been broken on the box, but it won’t have been kept in a wine cellar so would dealers go near it?
There will always be someone interested. The fact that it hasn’t been kept in pristine conditions will deter investors but a collector might still be willing offer a reasonable amount.
Don’t tell them it hasn’t been in a cellar?
They’ll never know until they open it, Shroedinger style Champagne. 
drink the champagne then fill the bottle with warm badger piss, reseal the box so nobody ever notices and then sell it to Boris Johnson.
If I was going near Boris with a refilled bottle, commerce would be the last thing on my mind.
Pricing for 93 seems to run £150-200. That’s where it’s been stored correctly
It’s not so easy to sell s/h wine that’s been stored in a kitchen or the like. When kept over years constant changes in temperature tend to spoil it. It’s very 50/50, sometimes it’s okay others it’s undrinkable.
Some one might be willing to give it a punt, if not pop it and keep your fingers crossed