I am seriously thinking about getting a Nikon D40x with 18-200VR lens. I am just costing everything up at the moment. Looking at polarizing filters, the cost seems to vary incredibly. The Nikon 72mm circular polarizing filter is £188, which is insane. I have seen other circular polarizing filters for £30. Will there be that much of a noticeable difference? I can't afford the Nikon filter right now, but does anyone have good cheaper suggestions?