Usually packaging errors don't add any value. If you found a collector who specifically collects those, then you might get a bit more for it, but I don't really think there are too many out there. If it was an error with the figure itself, then more collectors would be interested.
Toy Biz is quite famous for packaging errors. They were pretty common in a lot of their toy series in the 90's. We come across them occasionally in some of the other lines, like Marvel Universe and Spider-Man. We just ask for the normal price when it's added to the Figure Shop.