The roadmap says the expansion will release on the border of summer and fall (which would be the end of September if we consider the pixel placement of things on jpg to be something we can go by)
2 months after will be black friday and cyber monday, then a month later will be christmas.
One (or both) of those holidays will certainly see it go on sale, perhaps for 50% off as Dragonflight repeatedly was.
Might be worth saving your money and seeing how the expansion is playing out, maybe wait until the first few balance and bug fix patches make the rounds. Cause there’s no way hero talents, delves, and other stuff are going to work properly for the first couple months anyway. I mean, the first month of an expansion has always been riddled with poor balance and bugs, and that was before they laid off all their testers. Remember, we the paying customers are the testers now.
That’s why I buy my first, full priced, version. For my bot account. By the time I lose that account it’s on sale and I can buy it for me and all my buds so we can play together for a few months. Bliz really couldn’t have set it up any better.