I am not a huge Dune fan – like a fair number of folks, I think, I liked the first couple, and then was sort of meh on the later ones. But some folk really like the series, and now here is an omnibus of the first three books in the series (Dune, Dune Messiah, and Children of Dune) on sale for £0.99 as part of today’s Kindle UK Daily Deal. Which is a great price, and almost certainly only good for today only…
Buy The Great Dune Trilogy by Frank Herbert at Kindle UK
The trilogy is £0.99 at Kindle UK again. The link in the OP is still good.
Now an omnibus of the next three books is on sale in the UK for £0.99. The Second Great Dune Trilogy (no false modesty here 😁) contains: God Emperor of Dune, Heretics of Dune, and Chapter House Dune.
Kindle UK: https://www.amazon.co.uk/dp/B07GXSQHKY
Kobo UK: https://www.kobo.com/gb/en/ebook/the-second-great-dune-trilogy
Note that there was a Humble Bundle of Dune books for sale not too long ago, and the Gateway Collection of six titles was also on sale a while back, so check carefully before you buy!