Coswurv, That box will upscale the images but it will still not look as good as Sky HD as a true HD Image starts with the Higher number of pixels.

As for the Comet £99 deal, it appears it was an Xmas offer although I have seen some people post that they got a deal of Sky themselves for £199. May be worth giving them a call. I would sooner spend £200 on a Sky HD box than £150 on the one in the link.