Sky are rumoured to be slashing the Sky HD STB cost in July... £150 for new & existing customers (not including installation).
http://www.skyuser.co.uk/forum/sky-n...ge-sky-hd.html
But yeah, there is still the Sky HD subscription (to become the "Sky HD Mix" in July) at £10 per month, if you want the various Sky HD channels.
Although BBC HD & C4 HD are totally free - no need for a Sky HD subscription for those. But... if you get a Sky HD box from Sky and do not take out a Sky HD subscription, Sky charge you the full whack for the box (£400 IIRC).[so for that route, it's much cheaper to get one off eBay or somewhere & self-install, or wait for the Freesat HD PVR if you want Sky+ type features but also want free HD channels)]