Originally Posted by Whiternoise 
IYou can get basic models like that right up to £5k+. That said, in my opinion once you start paying more than the TV you should consider your priorities (and as you know, TV's can go WELL above £5k!).
My sound system cost 10x as much as my TV, though I listen to a lot of music through it and watch a lot of films and I really feel that it's worth it. In a strange way, I find a good sound system to be far more impressive than a good TV - and once you've heard one it's hard to go back.
There's nothing to stop you going into a hi-fi shop and saying that people have suggested you buy a decent surround sound kit, but you're not convinced it's worth it. Let them demo you some kit and see whether you think it's worth having a nice sound system for the money it would cost. If you don't think it's worth it then there's no obligation to buy anything.