I'm not understanding Imeo ! If pre-order day #1 you sell 1,000. Ithaka's , and day #2 you sell 1,500. Ithaka's , then that's it,  you stop pre-orders ?  That's all your going to make or sell is 2,500. and maybe 500. more for people that missed the pre-order ?
 Or is it , say you are going to make 3,000. Ithaka's and you sell 2,000 by day #2 of pre-order, so then you add more days till you sell all 3,000. ?
 See what I mean ?  I thought the pre-orders were to get a approximate number of  items make.  A general idea of the product demand.
 But you say your going to make just so many and 2 days is all your going to sell....  So then your going to sell 2 days worth of Ithaka's.
 And if you sell , say 500. each day and by day #2 it's 1,000. units sold.  So don't you think that's alot of people ordering in just 2 days ? 
I think you need to make it a (1) week long pre-order , and make that number of units , plus your extra's for inventory , at your official resellers , and others that did not have the money at the time or missed the pre-order.
 Oh well...LOL... I'm getting dizzy chasing my tail...LOL  ,  10-4  good buddy  ,  over and out !  And Merry Christmas Everyone !