We are here to offer the best advice though, and the best advice is not to drop the full budget on a system if need be, but instead to get what you need, and a little more (which the 560 Ti does), and then upgrade as you go, so you end up spending the same amount of money in say a 2-3 year period as you would otherwise, but you keep performance at the highest throughout by selling the "old" parts and putting a bit more money in.
By getting a new system every 3-4 years by the end of the first you are having to drop settings down, and by the 3rd or 4th, you are on lowest settings, rather than spending the same amount of money in those 3-4 years, and having it always on the highest with the same amount of money spent
=EDIT=
If someone asked "is a 6950 enough for 1080p?" you would say yes, good card, because the 69xx cards are AMD's top end, however that doesn't mean it is better than Nvidia's Mid-High end, which is what the 560 Ti is. You would be happy with saying a 6950 is enough for HD, simply because of AMD's marketing, but an equivalent Nvidia card isn't good enough, or rather isn't worth it because there is better. If someone comes on saying "I was thinking of getting a 6970", you wouldn't say "no, get a 6990, you get more power". It isn't worth it, as you get more and more powerful, you pay more and more for not a whole lot better performance, and in my mind, at the moment a 560 Ti/6950 is the cut off point, unless you NEED more power, which 1080p doesn't, you only need more if you are on multiple monitors or at high resolutions
