Best price I've seen for all 5 seasons (but be aware season 6 has been commissioned).
Still £35 on Amazon and Play !
Don't forget Quidco.
(ps - longtime lurker, 1st-time bargain post, apols if I've made any mistakes)
Price has now risen up from £15.99 to £17.99 Still a good price but no very nice of HMV!