Hi im after a polarizer filter for my 18-105mm Nikon kit Lens.As a newbie should i be looking to buy only a cheapie,as later on will probably upgrade to a better lens and if so which ones do you recommend.Or do i buy the best because there is alot of difference in the quality of the pics i will get,again which ones do you recommend and the best place to buy them.Appreciate any help,thanks.