Just looked back through my BC emails, I don't always open all of them up and they come to an account I don't check every day. Anyway, it does say "up to 90%" on each of my emails with a link through to the sale.
And this past Sunday afternoon around 1pm was when the first emails about the sale were sent to subscribers based on what I received. My email program shows the first few lines of the mail text and the beginning of each email was about Star Wars costumes (Of no interest to me so didn't bother to open up). But then after that down the page was the info on the Semi-Annual sale.

So actually people in the know have been buying costumes since Sunday. That was sneaky! Who knows what was available on clearance earlier...maybe some real nice stuff I could have used.

In past years there have always been a few very expensive costumes listed on the initial sale day that are marked way down and those get snapped up right away. Oh well, out of sight, out of mind or so the expression goes. Surprised no one else saw the early emails given how many members here have bought from them in the past and are subscribed.