Interesting. It's a good price but are they books I want to listen to? I read the Ringworld books sometime ago.
I've got Sharing Knife as paper copies; it's interesting. The world may be (or may not be) our world post an apocalyptic event (possibly a nuclear war). I would describe the books as science fantasy - the 'magic' may actually be psionics, and the setting is low tech, possibly equivalent to 18th Century. It comes across as early North America, not the initial exploration and First Nations resettlement, but pre-American Civil War. It's similar in style to Patricia Wrede's Frontier Magic series, and the standalone A Brother's Price from Wen Spencer (both I'd categorise as Alternate History, rather than Science Fantasy).
I have the first 2 Ringworld as paper books, but not the later ones. Ringworld I have as ebook as well; I started a re-read a while back but got distracted. I did think the societal mores described were very much an extrapolation of the 60s, and wasn't entirely happy.
David Farland (Dave Wolverton) and William Forstchen I've heard of but not read. Forstchen publishes SF over at Baen, but not the series in the bundle. The other author, William Sainsbury Smith, I've never heard of.
I'd say the bundle is worth it for the Bujolds alone, and the Nivens are icing on the cake (as it were). Given the retail price of audio books, this is a bargain and the books are unabridged.
Interestingly, if you click on the publisher link, it takes you to the paper website, not the audio website which is
https://www.blackstonewholesale.com/