Here in Ireland (it hasn't been Eire for about 50 years...), we do not receive, officially anyway, BBC HD as part of the HD channel package - although you can get it through the extra channels. No C4 HD here either - not sure if you can get that in the UK - and, obviously, no ITV HD.
Sky in Ireland has usually been more expensive than in the UK. HD hasn't really taken off here as the Irish channels RTE or TV3 do not have HD channels (unlikely to for a while as well) so I'd guess that Sky are really trying to make some money out of HD here. When I looked into HD here, the very friendly salesperson basically told me that it would cost too much and that I'd have to pay a fortune to move my exisitng Sky Plus box (as I already have an ordinary Sky box as Multiroom).
The Irish & UK markets are different for Sky remember. Here we do not have Sky Broadband for example and the SD channel packages are different. Comparing the 2 markets as though they are in the same place is, IMHO, a bit nonsensical..