Well this is a find.....
Puma are having a 30% off everything sale which you may already know about but Puma sponsors Arsenal and Dortmund so you can get 30% off the retail price on the football shirts via the official puma site. These shirts are full price on the official Arsenal site.
I know that no other retailer generally offers discount on current season kits so this is a great deal.
Price above represents men's sizes but boy's sizes are included in the offer.