I have the basic Virgin "M" broadband and find it fast enough for my needs, plus the phone package has the answering machine service and cheap international calls (in-laws live in Oz) - I pay £22 per month for that, from memory
For Sky, all the entertainment mixes, plus Sky Sports and HD mix - £50
The Sky HD+ box was on offer - £75 for the box, £30 for the install, £25 not to connect permanently to a phone line.
So thats one-off payment of £130 (some of which I will recoup by selling my HD recorder), and £72 for all services
It costs a little more than sticking to Virgin, but I am extremely pleased with the result. I had the standard Virgin box, not the V+, so I now have easy recording facilities and HD as well for my extra dosh.
I haven't bothered looking for more of a discount, I believe there is a good offer on at the moment for Sky broadband.
After spending circa 2k on a plasma panel and new AV amp, I thought it was crazy not to spend a little extra and provide them with a good HD source.
...and if I ever get strapped for cash I can use the dish for freesat instead, by which time they should have a decent amount of HD channels on show