This will only be available for a limited time. I will likely unpublish it in January or February so just a heads up. But in the mean time you can grab the first three books in the series for a 16% savings.
Also, the collection is on Netgalley if you happen to be a Netgalley reviewer. You can grab it here if you are… https://www.netgalley.com/catalog/book/155628