This could be something that you bought for a higher price than what most people would guess based on the item, or it could be something you bought for a normal price that has gained significant value as time has gone on.
What made me think of this question is a LEGO minifigure I got with my “The Hobbit: An Unexpected Journey” disc. It is Bilbo Baggins in a blue coat that was apparently only sold in that movie box only at Target stores. Even considering the exclusivity, I would have guessed maybe $10-20 for such a tiny piece of plastic, but there are sold listings on eBay from $80 to $225. I could possibly even get towards the higher end of that number since I still have everything in the original box in good condition. It’s not worth a ton compared to some other items people may own, but I think most people would not expect nearly that amount.
Not sure if these would be unexpectedly high values as most people know they fetch a little bit, but I have all my old N64 games still boxed with most of the original inserts too. The one I know most would be Conkers Bad Fur Day, that always seems to fetch a nice price.
A couple of my Funko Pop figures are possibly worth a few hundred but nothing more.
And I have the full set of Hobbit and Lord of the Rings Lego sets which I know go for a bit over the original price.
N64 games are pricey enough, but with the cardboard? Might as well consider them an investment! Lol