It may have sold out, Stephen. Some of these are down to limited quantities and are expected to sell out.Robert, when one clicks on the link you provided, there is a photo of a small list of books including Ranew's 'Solitude improved by Divine meditation'. However when one clicks on the next link 'View the sale', Ranew's book is not listed.
Personally I think Ranew's book should be read by every serious Christian. It is a gem. I said serious Christian because his argument can be hard to follow and can extend over a number of chapters. But it is worth it.