I'm not sure what someone would do with such a thing. If you open the box the value would drop a few thousand dollars. Leave it in the box and what's the point of owning it except maybe as an investment.
I bought a low mileage exotic car a few years back and was torn between driving it or keeping it garaged. I've have gotten more pleasure owning the same car with some miles on it for less money and just enjoying driving it.

A NIB 20 year old pin would normally be worth more than a restored one (at least to me). But since the box was water damaged you might want to remove it just to verify it's not damaged. I'm thinking you might get more if advertised as a "just unboxed to inspect - never played" pin than a "water damaged box" pin.