Or can you at least mention a new release?
I'm trying to advertise a boxed set with an individual book sale. If you think it's unwise to mess with the product description, I could add the boxed set under "series" as another way to advertise the boxed set new release. I plan to price the boxed set at a slightly reduced price as the whole package of individual books.
No, you can't mention a sale price on the product description.
Don't advertise another book on any book either.
Yes, add it to the series.
But if the series is long, then it won't be seen unless they press to slide.
What you can do is put a series list on the bottom of each product description, which can include the box set. I put all 8 of my series on every book. And use the A+ content to put a cover poster of the whole universe.
You have to do these things within the rules. But the rules are not to bad to work within these days, since the series became author controlled, and they added A+.