It was listed on the pre-order FAQ before the sim launched and for some time after, but you had to know where to look to find it.
If you had less hours, I might have suggested asking for a refunding with the reason that you did not understand it is more expensive to buy the upgrade in sim, and that you want to have it refunded so you could immediately buy the more expensive version through Steam.
But I do not think that would work in this instance.