Remember, aside from the standard hits, there is also the sketch as well as a chance at the redemptions. Considering single boxes can fetch $200+, I would expect a sealed case to have more of a premium as you know that the sketch hasn't been pulled.
As for making sense, ultra hot wax prices don't follow logic. Take a look at Inkworks boxes of Twilight. The absolute best card you can pull isn't exceedingly rare and can pull $300-$400 whereas the boxes would sell for well over that.