I think that everyone is forgetting that LEGO has transitioned to just-in-time production over the last couple of years. 5 years ago, they would have slotted production capacity months in advance and made 50,000 copies, and if they sold out it would be ~6 months before they could squeeze in another production slot. Now, LEGO can shift production lines between sets quickly, so they can make 5,000 a week to carefully control supply (i.e. avoid full distribution warehouses). This is a smart way to avoid overstock. However, it means that many different sets get packaged every week and when there is a fast seller like this one, the weekly capacity only has a limited flexibility to it. In other words, they can't (won't) stop producing all other sets in demand just to make more of this one. At some point, demand and supply will equalize and it will be more easily available at retail. I imagine that this set may set the record for the most number of different seal codes, when it finally retires.
Oh, and Villager - build the set. Its awesome!