The 1:100 variant cover by JH Williams III will have a special metallic bronze ink on the cover.
While the 1:200 variant cover by Dave McKean with a special metallic copper ink.
Retailers who match 95% of their orders of Sandman Overture #1 will get full returnability on every issue they order, so they might well decide to jump on.
Publication date is March 5th folks. Not long now.