Just stumbled upon BookLive’s 100 yen sale which only lasts for 1st of April. You might want to check out other vendors like BookWalker, maybe they offer similar discounts…?
So far I found the following books which I find interesting and might want to purchase:
The Little Prince (in Japanese)
One Story Five Minutes (essence of famous books like The Three Musketeers, The Nutcracker and the Mouse King, Anne of Green Gables, Twenty Thousand Leagues Under the Seas and more)
Anne of Green Gables (6 book set - in English, though)
Peter Rabbit series (Japanese + English)