Bought this the other night, absolutely amazing show detailing the early days of NASA right up until the more recent Hubble repair missions.
It's a 6 hour series and the price is for the HD version. If you want the SD version, it's about 3 quid less. (Don't forget, when buying HD versions, you get the SD version as well for your iPod/iPhone).
There's no UK price to check against (It's a Discovery Channel series) but on Amazon US, the DVD set is about £15.