I think people are assuming the ES is large because it took so long to sell out. I think it took so long because of the limiting factors of the customer base:
1) Life size busts have a smaller base than, say, 12" figures (both because of the price and their size).
2) The Dead line has a smaller base than Star Wars or Marvel (or most other lines Sideshow produces).
3) Even Dead collectors are somewhat saturated with Patient Zero products.
Any of these factors would decrease the potential customer base, but together they have a cumulative effect, sort of a subset of a subset. I'll be very surprised if the ES for the exclusive is more than 200. 150 seems the most reasonable to me. But if it is higher than 200, we can expect with absolute certainty to see a significant number of cancellations and declines when it ships. Just look at what's happening with the UC.