As has been stated above, the upcharge is for the privelege to read the content early. For me, there are two large benefits to this.

The prologue gives a large variety of content relating to the upcoming book which can be dissected and theorized. It also gives everyone who posts here (and sites like this) a chance to be involved in one last bevy of discussions and theories with fresh content before the end.

Also, I have always found the prologues of WoT to be the most arduous to read through. What with the tendency to focus on superfluous characters and tangential plotlines, I tend to find myself impatient to get through it and on to the more intriguing parts. The pre-release gives me an opportunity to enjoy the prologue in a way I wouldn't otherwise. Well worth the cost.



I find this analogy to be baseless. It would be accurate if the actual book's release omitted the prologue, requiring the purchase of this content. But that's not the case. A more appropriate analogy might be needing to be a subscription member of a gaming service to be allowed access to participate in beta testing.

Of course, just FYI, the content is marked as DRM free. So I'm sure you could find a way to get the content without paying for it, if it bothers you that much.