With the 25th of March being the date of the downfall of the Sauron and the fall of Barad-dûr, the Tolkien Society has for the last 11 years recognized March 25th as Tolkien Reading day.

Many online ebook retailers will offer steep discounts on the core books, The Silmarillion, and the extended Legendarium Histories as well as other books like his translation of Beowulf.

Kobo - steep discounts ($2.99 or less) on 30 books

Amazon* - Tolkien Page books appear to be same price as Kobo

Barnes & Noble* - Tolkien Page books appear to be same price as Kobo

* - I will update this link to a Tolkien Day specific page for this retailer if one becomes available. The have had specific pages in the past commemorating the day.