I'm watching Mad Men s.5 via a US iTunes account. It cost me $31.99 (£21.38) for the HD season pass. In the UK store Mad Men season 4 in HD retails for £28.99 and there's no sign of season 5.
Personally I don't like using "alternative means" to obtain US programming - as Jerry Seinfeld once lamented, "I don't wanna be a pirate!" - but the media companies deny the content to those willing to pay so what do they expect? I watched Game of Thrones and Boardwalk Empire thanks to friends who have Sky Atlantic and recorded it for me, and have "legitimised" that viewing by buying the box sets of both once available, but I will be in the minority. I'm not taking a moral high ground though and think that the media companies (Sky, HBO, AMC et al) encourage piracy with their draconian content strategy. Did they learn nothing from the music industry's collapse??
That Sky Atlantic's initial viewing figures (which exclude timeshifted viewing) are so low for the premiere, despite the hype, is hardly a surprise as it wasn't a popular show even on BBC4. But Mad Men is an expensive show to produce and you would think the producers would want to reach as broad a paying audience as possible, rather than just find the show as minority viewing available to a limited audience.