Blizzard sale?

What times of the year are vanilla WoW and the xpacs on sale?

Only before Christmas?

Usually just around black friday.

Usually around their 1-year, 2-year, 3-year, etc anniversary.
Possibly other times too, but definitely close to the anniversary of the game.

Blizzard just turned 20 years, so I suppose a sale might be on soon.

I hope someone posts on here to notify others if/when a sale happens. I have three odd slots to fill and i'd rather level one more group than three...

All i need is vanilla wow.

Well-I just upgraded 2 accounts to Wrath from BC-Blizz offered 15% discount for Cat included if that helps any.
I didn't see anything for Vanilla though