I agree with you and no doubt that there are great value for money products but I have found that some glass imperfections in some cheaper products can cause the artifacts that call such filters into question.. As you have spent your hard earned cash on your lenses makes sense to get something to protect and get the most from the optics.. With care there is no need for filters of this type at all.. But accidents can happen.. Its your choice.. The law of diminishing returns applies for that reason I go with something like Hoya rather than the Canon ones for my own camera as they cost half

Danny O'Byrne  http://www.digitalartzone.co.uk/

"All the technique in the world doesn't compensate for the inability to notice" Eliott Erwitt