I really think the 500f4 is the ultimate "middle class" big white.Does that make my 300 f/2.8 IS II low class? If so, it sure didn't feel that way when I paid my AMEX bill that month. I'm just kidding, but I've never heard the big whites discussed in terms of class
I'm just thinking about how the 400f2.8, 600f4, and 800f5.6 all seem to fit into roughly the same size and price category.
The 200-400+1.4xTC probably fits in there too, but just for the price.
I just did some cost/mm calculations though, and they do all end up roughly the same. Though the US dealers seem to set all big whites on the same cost/mm as the 300f2.8 bare, where Canadian dealers put the 500mm+ lenses closer to the cost/mm of the 300f2.8 with a 1.4x TC (including price of TC).
I think the difference may be in part due to MAP policies between the two Canon distributors. We've seen B&H give discounts when asked, though it's hard to say how close they would come to price matching.