The BBC store is the latest place to purchase online DVD's and episodes of doctor who, as well as it's spin off shows.
The store dedicates itself for a lot of things-having DVD's of episodes from every single doctor and series. It even put the exclusive power of the daleks on as an exclusive buy before even the DVD release.
Torchwood is among other related shows on the store, and now class joins it. Every Sunday, the latest episode of class will be available here
All 6 episodes so far are available, with the final two coming soon. The episodes will be available to buy individually for £1.89 each, and you can buy the whole of season 1 for £12.99.