Osprey Publishing is having a sale on all their books and pdfs on their website this weekend.
From the announcement:
For this weekend only, we have knocked 20% off all books on our website, including all series and general titles. Epubs and PDFs are also included, and Gold and Silver membership discounts will be stacked on top of the 20%.
The offer will last until the end of Easter Monday, so get cracking and make sure you take advantage!