this...if you want to go long, it get's expensive...be that the R&D...size of the optics...who knows...but it's going to cost you
this zoom is a whole new animal that canon has nothing else like right now...the ability to go from 200f4 to 500f5.6 with the flick of a switch and the twist of a zoom....the versatility of it is also why it's going to be a lot more $$
That versatility will also cut into sales of other Canon lenses, a point which Canon knows and will have built into the price.

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